Information on EC 2.4.1.21 - starch synthase (glycosyl-transferring)

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The expected taxonomic range for this enzyme is: Bacteria, Eukaryota, Archaea

EC NUMBER
COMMENTARY
2.4.1.21
-
RECOMMENDED NAME
GeneOntology No.
starch synthase (glycosyl-transferring)
REACTION
REACTION DIAGRAM
COMMENTARY
ORGANISM
UNIPROT ACCESSION NO.
LITERATURE
ADP-glucose + [(1->4)-alpha-D-glucosyl]n = ADP + [(1->4)-alpha-D-glucosyl]n+1
show the reaction diagram
-
-
-
-
REACTION TYPE
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
hexosyl group transfer
-
-
-
-
PATHWAY
KEGG Link
MetaCyc Link
Biosynthesis of secondary metabolites
-
glycogen biosynthesis I (from ADP-D-Glucose)
-
Metabolic pathways
-
Starch and sucrose metabolism
-
starch biosynthesis
-
SYSTEMATIC NAME
IUBMB Comments
ADP-glucose:(1->4)-alpha-D-glucan 4-alpha-D-glucosyltransferase
The accepted name varies according to the source of the enzyme and the nature of its synthetic product, e.g. starch synthase, bacterial glycogen synthase. Similar to EC 2.4.1.11 [glycogen(starch) synthase] but the preferred or mandatory nucleoside diphosphate sugar substrate is ADP-glucose. The entry covers starch and glycogen synthases utilizing ADP-glucose.
SYNONYMS
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
adenosine diphosphate glucose-starch glucosyltransferase
-
-
-
-
adenosine diphosphoglucose-starch glucosyltransferase
-
-
-
-
ADP-glucose starch synthase
-
-
-
-
ADP-glucose synthase
-
-
-
-
ADP-glucose transglucosylase
-
-
-
-
ADP-glucose-starch glucosyltransferase
-
-
-
-
ADP-glucose-starch glucosyltransferase
Q2HWR3
-
ADP-glucose-starch glucosyltransferase
Parachlorella kessleri 11 h
Q2HWR3
-
-
ADPG starch synthetase
-
-
-
-
ADPG-starch glucosyltransferase
-
-
-
-
AtSSII
-
-
CkGBSS
Q2HWR3
-
CkGBSS
Parachlorella kessleri 11 h
Q2HWR3
-
-
dull1
F2YI17
gene name
GBSS
-
-
GBSS
Parachlorella kessleri 11 h
Q2HWR3
-
-
GBSSI
-
-
GBSSI
B1B5Z0, B1B5Z1
-
glgA
Q9HH97
gene name
glgA
Q9HH97
gene name
-
glucosyltransferase, adenosine diphosphoglucose-starch
-
-
-
-
glycogen synthase
-
-
granule-bound starch synthase
-
-
granule-bound starch synthase
Q2HWR3
-
granule-bound starch synthase
Parachlorella kessleri 11 h
Q2HWR3
-
-
granule-bound starch synthase I
C9K223
-
granule-bound starch synthase I
-
-
granule-bound starch synthase I
-
-
granule-bound starch synthase I
B1B5Z0, B1B5Z1
-
OsGBSSII
-
-
OsSSIII-1
Q8W1P1
-
OsSSIII-2
Q8L8G9
-
OsSSIV-1
Q6UBQ7
-
OsSSIV-2
Q84VC7
-
PvSSII-1
-
-
SSIIc
A9QXF0
-
SSIIIa
-
-
starch synthase
-
-
starch synthase I
-
-
starch synthase I
-
-
starch synthase I
-
-
starch synthase I
-
-
starch synthase I
B1B5Z0, B1B5Z1
-
starch synthase I
-
-
starch synthase II
-
-
starch synthase II
-
-
starch synthase II
-
-
starch synthase II
-
-
starch synthase IIa
-
-
starch synthase IIa
-
-
starch synthase IIa
-
-
starch synthase III
-
-
starch synthase III
-
-
starch synthase III-1
Q8W1P1
-
starch synthase III-2
Q8L8G9
-
starch synthase IV
Q941L8
-
starch synthase IV-1
Q6UBQ7
-
starch synthase IV-2
Q84VC7
-
starch synthetase
-
-
-
-
starch-synthase III
-
-
TaSSIVb
Q941L8
-
CAS REGISTRY NUMBER
COMMENTARY
9030-10-8
-
ORGANISM
COMMENTARY
LITERATURE
SEQUENCE CODE
SEQUENCE DB
SOURCE
ecotype Columbia
-
-
Manually annotated by BRENDA team
starch synthase III
-
-
Manually annotated by BRENDA team
var. Columbia Col-0
Q9SAA5
Uniprot
Manually annotated by BRENDA team
var. Columbia Col-0
Q1WAB7
Uniprot
Manually annotated by BRENDA team
NRRL B1973
-
-
Manually annotated by BRENDA team
Arthrobacter sp. NRRL B1973
NRRL B1973
-
-
Manually annotated by BRENDA team
var. esculenta
-
-
Manually annotated by BRENDA team
soybean
-
-
Manually annotated by BRENDA team
barley
-
-
Manually annotated by BRENDA team
shrunken grain mutant M292
-
-
Manually annotated by BRENDA team
var. Himalaya 292, hull-less barley cultivar with a single nucleotide change in the gene encoding starch synthase IIa. This leads to loss of enzyme activity, resulting in a grain with less total starch and a higher proportion of amylose
-
-
Manually annotated by BRENDA team
cultivar Nipponbare and Kasalath
-
-
Manually annotated by BRENDA team
cultivar Nipponbare. Four allelic mutant lines of rice generated by retrotransposon Tos17 insertion and carrying SSI mutations expressed in endosperm, one containing a null mutation and three exhibiting different levels of SSI activity
-
-
Manually annotated by BRENDA team
genotype Tainung 67 and its two NaN3-induced mutants SA419 and SA418
-
-
Manually annotated by BRENDA team
indica variety Zhe733 and japonica variety Zhenongda104
SwissProt
Manually annotated by BRENDA team
japonica and indica varieties
-
-
Manually annotated by BRENDA team
L.cv.Zhe 733,Indica
-
-
Manually annotated by BRENDA team
rice
-
-
Manually annotated by BRENDA team
subsp. indica
SwissProt
Manually annotated by BRENDA team
var indica and var. japonica
-
-
Manually annotated by BRENDA team
strain 11 h
SwissProt
Manually annotated by BRENDA team
Parachlorella kessleri 11 h
strain 11 h
SwissProt
Manually annotated by BRENDA team
low-amylose (lam) mutant line (SIM 503)
-
-
Manually annotated by BRENDA team
starch synthase II
-
-
Manually annotated by BRENDA team
castor bean
-
-
Manually annotated by BRENDA team
at least 8 alleles of granule-bound starch synthase I
-
-
Manually annotated by BRENDA team
granule-bound starch synthase I
-
-
Manually annotated by BRENDA team
starch synthase III
-
-
Manually annotated by BRENDA team
isoenzymes I-IV
-
-
Manually annotated by BRENDA team
; cultivar BY535 with a high starch content and culitvar JM20 with a low starch content
-
-
Manually annotated by BRENDA team
cultivar HD 2285; cultivar WH 542
-
-
Manually annotated by BRENDA team
isoform SSIIc
UniProt
Manually annotated by BRENDA team
cultivar KPS1
-
-
Manually annotated by BRENDA team
granule-bound starch synthase I
-
-
Manually annotated by BRENDA team
teosinte
-
-
Manually annotated by BRENDA team
corn, ssp. mexicana
-
-
Manually annotated by BRENDA team
granule-bound isoenzymes I and II
-
-
Manually annotated by BRENDA team
granule-bound starch synthase I
-
-
Manually annotated by BRENDA team
isoenzymes I and II in leaf and kernel
-
-
Manually annotated by BRENDA team
isoform SSIIc
UniProt
Manually annotated by BRENDA team
isoform SSIII
UniProt
Manually annotated by BRENDA team
starch synthase I
-
-
Manually annotated by BRENDA team
starch synthase II
-
-
Manually annotated by BRENDA team
starch synthase SSIII
UniProt
Manually annotated by BRENDA team
starch synthases IIa and IIb
-
-
Manually annotated by BRENDA team
Zea saccharata
-
-
-
Manually annotated by BRENDA team
Zea saccharata
sweet corn
-
-
Manually annotated by BRENDA team
GENERAL INFORMATION
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
metabolism
-
starch synthesis
metabolism
-
granule-bound proteins involved in amylopectin synthesis are partitioned into the starch granule as a result of their association within protein complexes, and starch synthase IIa plays a crucial role in trafficking starch synthase I and starch branching enzyme IIb into the granule matrix. A mutant starch synthase IIa that has lost catalytic activity and is unable to bind to starch additionally leads to greatly reduced activities of starch synthase I and starch branching enzyme IIb
metabolism
-
glycogen synthesis occurs via ADP-glucose in Streptomyces coelicolor, with the pathway being strictly regulated in connection with other routes involved with oligo- and polysaccharides, as well as with antibiotic synthesis in the bacterium, metabolic scenario for glucose 6-phosphate partitioning, overview
physiological function
-
function of isoform SSIV in the priming process of starch granule formation. SSIV is necessary and sufficient to establish the correct number of starch granules observed in wild-type chloroplasts. The role of SSIV in granule seeding can be replaced, in part, by SSIII. The simultaneous elimination of both proteins prevents Arabidopsis thaliana from synthesizing starch. The soluble starch synthase activity in ssI ssII ssIV mutant plants is 32% of the activity determined in wild-type plants, whereas no soluble SS activity can be detected in ssI ssII ssIII mutant plants
physiological function
-
construction of double mutant isoforms ss1- ss2- or ss1- ss3- lines using confirmed null mutations. Double mutant plants develop similarly to the wild type, although they accumulate less leaf starch in both short-day and long-day diurnal cycles. Lines containing only SS2 and SS4, or SS3 and SS4, are able to produce substantial amounts of starch granules. In both double mutants the residual starch is structurally modified including higher ratios of amylose to amylopectin, altered glucan chain length distribution within amylopectin, abnormal granule morphology, and altered placement of alpha(1-6) branch linkages relative to the reducing end of each linear chain. Starch Ssynthase activity affects not only chain elongation but also the net result of branch placement accomplished by the balanced activities of starch branching enzymes and starch debranching enzymes. Isoform SS3 partially overlaps in function with isoform SS1 for the generation of short glucan chains within amylopectin
physiological function
-
construction of double mutants defective in isoforms SSI and SSIIIa. In the F2 generation, two opaque seed types were found to have either the ss1ss1/SS3ass3a or the SS1ss1/ss3ass3a genotype. The endosperm of the two types of opaque seeds displays lower starch synthase activity and contains the unique starch with modified fine structure, round-shaped starch granules, high amylose content, and specific physicochemical properties. The seed weight is about 90% of that of the wild type. The amount of granule-bound starch synthase I and the activity of ADP-glucose diphosphorylase are higher than in the wild type and parent mutant lines. The double-recessive homozygous mutant prepared from both ss1 and ss3a null mutants is considered sterile, while the mutant produced by the leaky ss1 mutant with the ss3a null mutant is fertile
physiological function
F2YI17
double mutant endosperms which are affected in both isoform SSIII and ISA2, encoding a noncatalytic subunit of heteromeric isoamylase-type starch-debranching enzyme, are starch deficient and accumulate phytoglycogen. Despite lack of functional isa2, ISA1 homomeric enzyme complexes assemble in both double mutants and are enzymatically active in vitro. Thus, SSIII is required for normal starch crystallization and the prevention of phytoglycogen accumulation when the only isoamylase-type debranching activity present is ISA1 homomer, but not in the wild-type condition, when both ISA1 homomer and ISA1/ISA2 heteromer are present
SUBSTRATE
PRODUCT                      
REACTION DIAGRAM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
(Substrate)
LITERATURE
(Substrate)
COMMENTARY
(Product)
LITERATURE
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
ADP-glucose + (1,4-alpha-D-glucosyl)n
ADP + (1,4-alpha-D-glucosyl)n+1
show the reaction diagram
-
-
-
-
?
ADP-glucose + (1,4-alpha-D-glucosyl)n
ADP + (1,4-alpha-D-glucosyl)n+1
show the reaction diagram
-
granule-bound starch synthase I is responsible for biosynthesis of extra-long unit chains of amylopectin in rice
-
-
?
ADP-glucose + (1,4-alpha-D-glucosyl)n
ADP + (1,4-alpha-D-glucosyl)n+1
show the reaction diagram
B1B5Z0, B1B5Z1
granule-bound starch synthase I is responsible for biosynthesis of extra-long unit chains of amylopectin in rice
-
-
?
ADP-glucose + (1,4-alpha-D-glucosyl)n
ADP + (1,4-alpha-D-glucosyl)n+1
show the reaction diagram
-
SSIII is able to partially function in production of DP12 to DP25 chains. SSIII is not required for the normal population of these chains
-
-
?
ADP-glucose + (1,4-alpha-D-glucosyl)n
ADP + (1,4-alpha-D-glucosyl)n+1
show the reaction diagram
-
the activity of SSII is required in Arabidopsis for production of the normal frequency of amylopectin chains of DP12 to DP25. None of the other SS classes can completely compensate for loss of SSII, however, SSIII is able to partially function in production of DP12 to DP25 chains
-
-
?
ADP-glucose + (1,4-alpha-D-glucosyl)n
ADP + (1,4-alpha-D-glucosyl)n+1
show the reaction diagram
Q1WAB7
recombinant SSIII-CD uses with more efficiency rabbit muscle glycogen than amylopectin as primer and displays a high apparent affinity for ADP-Glc
-
-
?
ADP-glucose + (1,4-alpha-D-glucosyl)n
ADP + (1,4-alpha-D-glucosyl)n+1
show the reaction diagram
Q9SAA5
SSIII uses preferentially ADP-glucose, although UDP-glucose can also be used as a sugar donor substrate. the N-terminal starch-binding domains have a regulatory role, showing a starch binding capacity and modulating the catalytic properties of SSIII
-
-
?
ADP-glucose + (1,4-alpha-glucosyl)n
ADP + (1,4-alpha-glucosyl)n+1
show the reaction diagram
-
-
-
-
?
ADP-glucose + (1,4-alpha-glucosyl)n
ADP + (1,4-alpha-glucosyl)n+1
show the reaction diagram
-
amylopectin chains are synthesized by the coordinated actions of SSI, SSIIa, and SSIIIa isoforms
-
-
?
ADP-glucose + (1,4-alpha-glucosyl)n
ADP + (1,4-alpha-glucosyl)n+1
show the reaction diagram
-
function of SSI is mainly involved in the synthesis of small outer chains during amylopectin cluster synthesis
-
-
?
ADP-glucose + (1,4-alpha-glucosyl)n
ADP + (1,4-alpha-glucosyl)n+1
show the reaction diagram
-, Q2HWR3
low CO2 level up-regulates GBSS biosynthesis at the transcriptional level
-
-
?
ADP-glucose + (1,4-alpha-glucosyl)n
ADP + (1,4-alpha-glucosyl)n+1
show the reaction diagram
-
SSI regulates the population of short chains. Low activity of SSI gives rise to the decrease of short chains in amylopectin of indica rice varieties, suggesting that SSI effects the differences in physicochemical properties between the varieties
-
-
?
ADP-glucose + (1,4-alpha-glucosyl)n
ADP + (1,4-alpha-glucosyl)n+1
show the reaction diagram
-
SSII is a starch synthase for the synthesis of both transit and storage starch
-
-
?
ADP-glucose + (1,4-alpha-glucosyl)n
ADP + (1,4-alpha-glucosyl)n+1
show the reaction diagram
Parachlorella kessleri 11 h
Q2HWR3
low CO2 level up-regulates GBSS biosynthesis at the transcriptional level
-
-
?
ADP-glucose + 6'''-alpha-maltotriosyl-maltohexaose
ADP + 6''''-alpha-maltotetrasyl-maltohexaose
show the reaction diagram
-
-
starch synthase II elongates only the maltotriose chain
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
-
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
-
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
-
-
-
-
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
-
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
-
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
-
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
Zea saccharata
-
-
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
2 isoenzymes, 1 isoenzyme synthesizes a polyglucan in the absence of primer
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
citrate independent enzyme requires a glucan primer e.g. rabbit liver glycogen
-
r
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
citrate independent enzyme requires a glucan primer e.g. rabbit liver glycogen
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
citrate independent enzyme requires a glucan primer e.g. rabbit liver glycogen
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
citrate independent enzyme requires a glucan primer e.g. rabbit liver glycogen
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
citrate independent enzyme requires a glucan primer e.g. rabbit liver glycogen
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
citrate independent enzyme requires a glucan primer e.g. rabbit liver glycogen
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
citrate independent enzyme requires a glucan primer e.g. rabbit liver glycogen
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
citrate independent enzyme requires a glucan primer e.g. rabbit liver glycogen
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
citrate independent enzyme requires a glucan primer e.g. rabbit liver glycogen
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
citrate independent enzyme requires a glucan primer e.g. rabbit liver glycogen
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
citrate independent enzyme requires a glucan primer e.g. rabbit liver glycogen
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
citrate independent enzyme requires a glucan primer e.g. rabbit liver glycogen
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
citrate independent enzyme requires a glucan primer e.g. rabbit liver glycogen
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
citrate independent enzyme requires a glucan primer e.g. rabbit liver glycogen
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
citrate independent enzyme requires a glucan primer e.g. rabbit liver glycogen
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
enzyme shows both primed and unprimed activity
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
glucosyl acceptor: oyster glycogen
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
glucosyl acceptor: oyster glycogen
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
glucosyl acceptor: oyster glycogen
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
glucosyl acceptor: oyster glycogen
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
glucosyl acceptor: oyster glycogen
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
glucosyl acceptor: oyster glycogen
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
glucosyl acceptor: oyster glycogen
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
glucosyl acceptors: maltose, maltotriose, maltotetraose and maltoheptaose
-
r
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
granule-bound isoenzyme I shows higher activity with glycogen as primer than with amylopectin
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
glucosyl acceptor: starch
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
glucosyl acceptor: starch
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
glucosyl acceptor: starch
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
glucosyl acceptor: starch
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
Zea saccharata
-
glucosyl acceptor: starch
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
glucosyl acceptor: bovine liver glycogen
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
no activity with UDPglucose
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
specific for ADPglucose
-
-
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
Zea saccharata
-
glucosyl acceptors: phytoglycogen, maltotriose, maltotetraose or maltopentaose
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
enzyme shows both primed activity with amylopectin as glucose acceptor and unprimed activity in the presence of high citrate and bovine serum albumin, 4fold lower activity with UDPglucose instead of ADPglucose
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
granule-bound starch synthase I
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
less than 5% activity with UDPglucose and GDPglucose instead of ADPglucose, primed and unprimed reaction
-
-
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
glucosyl acceptors: Arthrobacter glycogen, potato starch, maltose and maltotriose
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
glucosyl acceptors: amylopectin beta-limit dextrin, glycogen E. coli beta-limit dextrin, maltose and maltotriose, 4 isoenzymes, isoenzyme III shows unprimed activity, no activity with UDPglucose and glucose 1-phosphate
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
glucosyl acceptor: amylose
-
r
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
glucosyl acceptor: amylose
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
glucosyl acceptor: amylose
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
glucosyl acceptor: amylose
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
glucosyl acceptor: amylopectin
-
-
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
glucosyl acceptor: amylopectin
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
glucosyl acceptor: amylopectin
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
glucosyl acceptor: amylopectin
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
glucosyl acceptor: amylopectin
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
glucosyl acceptor: amylopectin
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
glucosyl acceptor: amylopectin
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
glucosyl acceptor: amylopectin
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
glucosyl acceptor: amylopectin
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
glucosyl acceptor: amylopectin
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
glucosyl acceptor: amylopectin
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
Zea saccharata
-
glucosyl acceptor: amylopectin
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
citrate stimulates starch synthesis in the absence of primer
-
-
-
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
citrate stimulates starch synthesis in the absence of primer
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
granule-bound starch synthase I synthesizes the amylose component of starch
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
involved in starch biosynthesis
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
involved in starch biosynthesis
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
involved in amylose synthesis in the pericarp
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
two insertion mutations at the AtSS3 gene locus, termed Atss3-1 and Atss3-2, condition complete loss of SSIII activity and prevent normal gene expression at both the mRNA and protein levels. Total SS activity is increased in both Atss3 mutants and a specific SS activity appears to be upregulated. In addition to its expected direct role in starch assembly, SSIII also has a negative regulatory function in the biosynthesis of transient starch in Arabidopsis
-
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
Arthrobacter sp. NRRL B1973
-
citrate independent enzyme requires a glucan primer e.g. rabbit liver glycogen, glucosyl acceptors: Arthrobacter glycogen, potato starch, maltose and maltotriose, glucosyl acceptor: amylose, glucosyl acceptor: amylopectin
-
?
ADP-glucose + amylopectin
ADP + ?
show the reaction diagram
-
-
-
-
?
ADP-glucose + amylopectin
ADP + ?
show the reaction diagram
Zea saccharata
-
-
-
-
-
ADP-glucose + amylopectin
ADP + ?
show the reaction diagram
A4F2M4, -
N-domain of SSIII functions as a carbohydrate-binding module
-
-
?
ADP-glucose + glycogen
ADP + ?
show the reaction diagram
-
-
-
-
?
ADP-glucose + glycogen
ADP + ?
show the reaction diagram
-
-
-
-
?
ADP-glucose + glycogen
ADP + ?
show the reaction diagram
-
-
-
-
-
ADP-glucose + glycogen
ADP + ?
show the reaction diagram
A4F2M4, -
N-domain of SSIII functions as a carbohydrate-binding module
-
-
?
ADP-glucose + maltopentaose
ADP + maltohexaose
show the reaction diagram
-
-
granule-bound starch synthase I, smaller amounts of longer malto-oligosaccharides are also produced suggesting that starch synthase I adds 1 or more glucose units to the primer
?
ADP-glucose + maltose
ADP + maltotriose + maltotetraose
show the reaction diagram
-
-
-
?
ADP-glucose + maltotriose
ADP + maltotetraose
show the reaction diagram
-
-
-
-
ADP-glucose + maltotriose
ADP + maltotetraose
show the reaction diagram
-
-
-
?
ADP-glucose + maltotriose
ADP + maltotetraose
show the reaction diagram
-
-
granule-bound starch synthase I synthesizes maltotetraose and several higher maltose-oligosaccharides
?
ADP-glucose + maltotriose
ADP + maltotetraose
show the reaction diagram
-
-
starch synthase II adds only 1 glucose unit to the primer
?
ADP-glucose + maltotriose
ADP + maltotetraose
show the reaction diagram
-
-
starch synthase II adds only 1 glucose unit to the primer
?
ADP-glucose + maltotriose
ADP + maltotetraose
show the reaction diagram
-
6.4fold activation of maltotriose elongation by granule-bound starch synthase I by amylopectin promoting a processive mode of maltotriose elongation
-
-
ADP-glucose + [(1->4)-alpha-D-glucosyl]n
ADP + [(1->4)-alpha-D-glucosyl]n+1
show the reaction diagram
-
glycogen synthase exhibits specificity in the use of ADP-glucose to elongate alpha-1,4-glucan chains in the polysaccharide, substrate is rabbit liver glycogen
-
-
?
dADPglucose + alpha-1,4-polyglucan
dADP + alpha-1,4-polyglucan
show the reaction diagram
-
-
-
?
dADPglucose + alpha-1,4-polyglucan
dADP + alpha-1,4-polyglucan
show the reaction diagram
Zea saccharata
-
8% of activity with ADPglucose
-
?
dADPglucose + alpha-1,4-polyglucan
dADP + alpha-1,4-polyglucan
show the reaction diagram
Arthrobacter sp. NRRL B1973
-
-
-
?
n ADP-glucose
n ADP + [(1-4)-alpha-D-glucosyl]n
show the reaction diagram
-
-
-
-
?
UDP-glucose + (1,4-alpha-D-glucosyl)n
UDP + (1,4-alpha-D-glucosyl)n+1
show the reaction diagram
-
-
-
-
-
UDP-glucose + (1,4-alpha-D-glucosyl)n
UDP + (1,4-alpha-D-glucosyl)n+1
show the reaction diagram
Q9SAA5
SSIII uses preferentially ADP-glucose, although UDP-glucose can also be used as a sugar donor substrate
-
-
?
methyl-6'-alpha-maltosyl-alpha-maltotrioside + ADP-glucose
?
show the reaction diagram
-
SSII catalyses an equimolar and non-processive elongation reaction of this substrate. Both of the non-reducing ends of methyl 6'-alpha-maltosyl-6'-maltotrioside are extended equally resulting in two hexasaccharide products in nearly equal amounts
-
-
?
additional information
?
-
-
a defect in starch synthase IIa causes that short A-chains can not reach a sufficient length for branching enzymes to act on them to produce B1-chains
-
-
-
additional information
?
-
-
amylose in rice leaves is synthesized by OsGBSSII. Two independent pathways may be involved in OsGBSSII expression: sugar-regulating pathway, which is glycolysis-dependent, and an endogenous circadian rhythm-regulated pathway. N-starvation-induced OsGBSSII expression may depend on the sugar-regulating pathway
-
-
-
additional information
?
-
-
the activity of starch synthase IIa determines the type of amylopectin structure of rice starch to be either the typical indica-type or japonica-type, by playing a specific role in the synthesis of the long B1 chains by elongating short A and B1 chains, notwithstanding the presence of functional two additional SSII genes, a single SSI gene, two SSIII genes, and two SSIV genes in the rice plants. Val737 and Leu781 are essential not only for the optimal SSII1 activity, but also for the capacity to synthesize indica-type amylopectin
-
-
-
additional information
?
-
-
the starch synthase isoenzymes PvSSI and PvSSII-1 are responsible for synthesis of transistory starch and for the synthesis of storage starch in early developing seeds
-
-
-
additional information
?
-
-
amylose-free transgenic sweet potato plants are produced by inhibiting sweet potato GBSSI gene expression through RNA interference
-
-
-
additional information
?
-
-
the barley shrunken grain mutant M292 has a novel high-amylose starch phenotype caused by a mutation in the starch synthase IIa gene (SsIIa) located at the starch excess-6 (sex6) locus on chromosome 7H of barley. The loss of SSIIa enzyme activity leads to a decrease in amylopectin synthesis to less than 20% of the levels found in wild-type grains
-
-
-
additional information
?
-
-
potato starch-synthase synthesizes alpha-(1-4)-linked amylose chains de novo without the need of a primer. D-Glucopyranosyl and D-glucanyl starch chains are covalently attached to the active-site of starch synthase during catalysis. D-Glucose is added to the reducing-end of the growing chain processively, suggesting a two catalytic-site insertion mechanism
-
-
-
NATURAL SUBSTRATES
NATURAL PRODUCTS
REACTION DIAGRAM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
(Substrate)
LITERATURE
(Substrate)
COMMENTARY
(Product)
LITERATURE
(Product)
REVERSIBILITY
r=reversible
ir=irreversible
?=not specified
ADP-glucose + (1,4-alpha-D-glucosyl)n
ADP + (1,4-alpha-D-glucosyl)n+1
show the reaction diagram
-
granule-bound starch synthase I is responsible for biosynthesis of extra-long unit chains of amylopectin in rice
-
-
?
ADP-glucose + (1,4-alpha-D-glucosyl)n
ADP + (1,4-alpha-D-glucosyl)n+1
show the reaction diagram
B1B5Z0, B1B5Z1
granule-bound starch synthase I is responsible for biosynthesis of extra-long unit chains of amylopectin in rice
-
-
?
ADP-glucose + (1,4-alpha-D-glucosyl)n
ADP + (1,4-alpha-D-glucosyl)n+1
show the reaction diagram
-
SSIII is able to partially function in production of DP12 to DP25 chains. SSIII is not required for the normal population of these chains
-
-
?
ADP-glucose + (1,4-alpha-D-glucosyl)n
ADP + (1,4-alpha-D-glucosyl)n+1
show the reaction diagram
-
the activity of SSII is required in Arabidopsis for production of the normal frequency of amylopectin chains of DP12 to DP25. None of the other SS classes can completely compensate for loss of SSII, however, SSIII is able to partially function in production of DP12 to DP25 chains
-
-
?
ADP-glucose + (1,4-alpha-glucosyl)n
ADP + (1,4-alpha-glucosyl)n+1
show the reaction diagram
-
amylopectin chains are synthesized by the coordinated actions of SSI, SSIIa, and SSIIIa isoforms
-
-
?
ADP-glucose + (1,4-alpha-glucosyl)n
ADP + (1,4-alpha-glucosyl)n+1
show the reaction diagram
-
function of SSI is mainly involved in the synthesis of small outer chains during amylopectin cluster synthesis
-
-
?
ADP-glucose + (1,4-alpha-glucosyl)n
ADP + (1,4-alpha-glucosyl)n+1
show the reaction diagram
-, Q2HWR3
low CO2 level up-regulates GBSS biosynthesis at the transcriptional level
-
-
?
ADP-glucose + (1,4-alpha-glucosyl)n
ADP + (1,4-alpha-glucosyl)n+1
show the reaction diagram
-
SSI regulates the population of short chains. Low activity of SSI gives rise to the decrease of short chains in amylopectin of indica rice varieties, suggesting that SSI effects the differences in physicochemical properties between the varieties
-
-
?
ADP-glucose + (1,4-alpha-glucosyl)n
ADP + (1,4-alpha-glucosyl)n+1
show the reaction diagram
-
SSII is a starch synthase for the synthesis of both transit and storage starch
-
-
?
ADP-glucose + (1,4-alpha-glucosyl)n
ADP + (1,4-alpha-glucosyl)n+1
show the reaction diagram
Parachlorella kessleri 11 h
Q2HWR3
low CO2 level up-regulates GBSS biosynthesis at the transcriptional level
-
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
granule-bound starch synthase I synthesizes the amylose component of starch
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
involved in starch biosynthesis
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
involved in starch biosynthesis
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
involved in amylose synthesis in the pericarp
-
?
ADP-glucose + alpha-1,4-polyglucan
ADP + alpha-1,4-polyglucan
show the reaction diagram
-
two insertion mutations at the AtSS3 gene locus, termed Atss3-1 and Atss3-2, condition complete loss of SSIII activity and prevent normal gene expression at both the mRNA and protein levels. Total SS activity is increased in both Atss3 mutants and a specific SS activity appears to be upregulated. In addition to its expected direct role in starch assembly, SSIII also has a negative regulatory function in the biosynthesis of transient starch in Arabidopsis
-
-
?
ADP-glucose + [(1->4)-alpha-D-glucosyl]n
ADP + [(1->4)-alpha-D-glucosyl]n+1
show the reaction diagram
-
glycogen synthase exhibits specificity in the use of ADP-glucose to elongate alpha-1,4-glucan chains in the polysaccharide
-
-
?
additional information
?
-
-
a defect in starch synthase IIa causes that short A-chains can not reach a sufficient length for branching enzymes to act on them to produce B1-chains
-
-
-
additional information
?
-
-
amylose in rice leaves is synthesized by OsGBSSII. Two independent pathways may be involved in OsGBSSII expression: sugar-regulating pathway, which is glycolysis-dependent, and an endogenous circadian rhythm-regulated pathway. N-starvation-induced OsGBSSII expression may depend on the sugar-regulating pathway
-
-
-
additional information
?
-
-
the activity of starch synthase IIa determines the type of amylopectin structure of rice starch to be either the typical indica-type or japonica-type, by playing a specific role in the synthesis of the long B1 chains by elongating short A and B1 chains, notwithstanding the presence of functional two additional SSII genes, a single SSI gene, two SSIII genes, and two SSIV genes in the rice plants. Val737 and Leu781 are essential not only for the optimal SSII1 activity, but also for the capacity to synthesize indica-type amylopectin
-
-
-
additional information
?
-
-
the starch synthase isoenzymes PvSSI and PvSSII-1 are responsible for synthesis of transistory starch and for the synthesis of storage starch in early developing seeds
-
-
-
additional information
?
-
-
amylose-free transgenic sweet potato plants are produced by inhibiting sweet potato GBSSI gene expression through RNA interference
-
-
-
METALS and IONS
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
Cs+
-
below 20 mM, slight activation, concentrations higher than 20 mM abolish activation by K+ and Rb+
K+
-
slight activation
K+
-
50-100 mM, marked activation
K+
-
20-30% activation
Li+
-
below 20 mM, slight activation, concentrations higher than 20 mM abolish activation by K+ and Rb+
Mg2+
-
slight activation
Mg2+
-
1.5fold activation at 10 mM
Mn2+
-
10 mM, 47% of the activity with Mg2+
Na+
-
below 20 mM, slight activation, concentrations higher than 20 mM abolish activation by K+ and Rb+
NH4+
-
below 20 mM, slight activation, concentrations higher than 20 mM abolish activation by K+ and Rb+
Rb+
-
50-100 mM, marked activation
INHIBITORS
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
IMAGE
adenosine
Zea saccharata
-
0.7 mM, 30% inhibition
ADP
-
0.1 mM, 26% inhibition
ADP
Zea saccharata
-
0.7 mM, 30% inhibition
Ammonium molybdate
Zea saccharata
-
7 mM, complete inhibition
AMP
Zea saccharata
-
0.7 mM, 30% inhibition
ATP
-
0.1 mM, 22% inhibition
ATP
Zea saccharata
-
-
CaCl2
Zea saccharata
-
0.8 mM, 35% inhibition
Calcium calmodulin
-
granule-bound starch synthase, inhibition is prevented by chlorpromazine
-
Co2+
-
over 90% inhibition
CoCl2
Zea saccharata
-
4 mM, 70% inhibition
Cu2+
-
significant inhibition
Cu2+
-
over 90% inhibition
D-glucono-1,5-lactone
-
inhibition of glycogen synthase I and II
dADPglucose
Zea saccharata
-
1 mM, 30% inhibition
HgCl2
Zea saccharata
-
0.3 mM, complete inhibition
hydroquinone
Zea saccharata
-
5 mM, complete inhibition
MgCl2
Zea saccharata
-
-
MnCl2
Zea saccharata
-
7 mM, 30% inhibition
Ni2+
-
over 90% inhibition
p-chloromercuribenzoate
-
0.002 mM, 50% inhibition, 0.01 mM, 90% inhibiton
p-chloromercuribenzoate
Zea saccharata
-
7 mM, complete inhibition
pyridoxal-5'-phosphate
-
inactivates starch synthase IIa, ADP-glucose protects from inactivation
Zn2+
-
over 90% inhibition
ZnSO4
Zea saccharata
-
7 mM, complete inhibition
ACTIVATING COMPOUND
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
IMAGE
1,4-alpha-Glucan branching enzyme
-
EC 2.4.1.18, stimulation of unprimed reaction
-
ammonium sulfate
-
500 mM, 4fold activation of unprimed starch synthesis
ammonium sulfate
-
-
ammonium sulfate
-
strong activation of unprimed synthesis
Amylopectin
-
50 mg/ml, 6fold activation of granule-bound starch synthase I
beta-Lactoglobulin
-
activation of unprimed reaction
-
Bovine plasma albumin
-
activation of unprimed reaction
-
Bovine plasma albumin
-
activation
-
citrate
-
500 mM, 20fold activation of unprimed starch synthesis
citrate
-
500 mM, strong activation of unprimed reaction
citrate
-
500 mM, 9.3fold activation of granule-bound starch synthase I, 1.8 fold activation of starch synthase II
glutathione
-
activation
Hemoglobin
-
activation of unprimed reaction
-
Myoglobin
-
activation of unprimed reaction
-
n-Propanol
-
85%, activation
NaF
-
500 mM, strong activation of unprimed reaction
ovomucoid
-
activation of unprimed reaction
-
potassium acetate
-
500 mM, strong activation of unprimed reaction
Sodium acetate
-
500 mM, strong activation of unprimed reaction
succinate
-
500 mM, 6fold activation of unprimed starch synthesis
Isopropanol
-
above 70%, activation
additional information
-
peak of activities at the 28th day post anthesis, higher activity in the cultivar with a high starch content
-
KM VALUE [mM]
KM VALUE [mM] Maximum
SUBSTRATE
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
IMAGE
0.1
-
ADP-glucose
-
mutant enzyme K193Q, glycogen as primer
0.11
-
ADP-glucose
-
wild-type enzyme, amylopectin as primer
0.13
-
ADP-glucose
-
wild-type enzyme, glycogen as primer
0.14
-
ADP-glucose
-
mutant enzyme K193Q, amylopectin as primer
0.15
-
ADP-glucose
-
mutant enzyme K193R, amylopectin as primer; mutant enzyme K193R, glycogen as primer
0.17
-
ADP-glucose
-
mutant enzyme K193E, glycogen as primer
0.22
-
ADP-glucose
-
mutant enzyme K193E, amylopectin as primer
0.22
-
ADP-glucose
A4F2M4, -
pH 8.0, 30C, at 10 mg/ml amylopectin
0.28
-
ADP-glucose
-
catalytic domain
0.32
-
ADP-glucose
A4F2M4, -
pH 8.0, 30C,at 10 mg/ml glycogen
0.45
-
ADP-glucose
-
25C
0.59
-
ADP-glucose
-
catalytic domain co-expressed with starch-binding domain 3 and large part of starch-binding domain 2
0.62
-
ADP-glucose
-
catalytic domain co-expressed with starch-binding domains 23
0.71
-
ADP-glucose
-
45C
0.81
-
ADP-glucose
-
catalytic domain co-expressed with starch-binding domain 2 and part of starch-binding domain 3
0.95
-
ADP-glucose
-
catalytic domain co-expressed with starch-binding domains 123
1.68
-
ADP-glucose
-
truncated protein lacking starch binding domain 1 and large part of starch binding domain 2
1.74
-
ADP-glucose
-
truncated protein lacking starch-binding domains 12
1.77
-
ADP-glucose
-
truncated protein lacking starch binding domain 1 and medium part of starch binding domain 2
1.89
-
ADP-glucose
-
25C
2
-
ADP-glucose
-
45C
2.39
-
ADP-glucose
-
truncated protein lacking starch binding domain 1 and small part of starch binding domain 2
2.56
-
ADP-glucose
-
truncated protein lacking starch-binding domain 1
4.08
-
ADP-glucose
-
wild-type
0.000164
-
ADPglucose
-
-
0.033
-
ADPglucose
-
-
0.035
-
ADPglucose
-
-
0.035
-
ADPglucose
-
glycogen synthases I and II
0.05
0.1
ADPglucose
-
-
0.05
-
ADPglucose
-
granule-bound isoenzyme II from waxy maize
0.053
-
ADPglucose
-
starch synthase I, primer amylopectin
0.07
-
ADPglucose
-
starch synthase II, 5 mg/ml amylopectin
0.077
-
ADPglucose
-
-
0.09
-
ADPglucose
-
granule-bound isoenzyme I from waxy maize
0.1
0.12
ADPglucose
-
soluble isoenzymes
0.11
0.22
ADPglucose
-
-
0.11
-
ADPglucose
-
granule-bound isoenzyme II
0.11
-
ADPglucose
-
isoenzyme II, primed reaction
0.11
-
ADPglucose
-
recombinant starch synthase IIa
0.11
-
ADPglucose
-
starch synthase I, primer amylopectin, 500 mM citrate
0.12
-
ADPglucose
-
recombinant starch synthase IIb
0.14
-
ADPglucose
-
granule-bound isoenzyme I
0.15
-
ADPglucose
-
isoenzyme III
0.17
-
ADPglucose
-
isoenzyme I, primed reaction
0.18
-
ADPglucose
-
starch synthase I, presence of 500 mM citrate
0.2
-
ADPglucose
-
isoenzyme IV, primed reaction
0.2
-
ADPglucose
-
isoenzyme I
0.22
-
ADPglucose
-
isoenzyme III, primed reaction
0.24
-
ADPglucose
-
starch synthase I, absence of citrate
0.25
-
ADPglucose
-
isoenzyme IV
0.29
-
ADPglucose
-
synthase I, absence of citrate
0.29
-
ADPglucose
-
isoenzyme II
0.3
-
ADPglucose
-
starch synthase II, primer amylopectin, 500 mM citrate
0.48
-
ADPglucose
-
synthase II, absence of citrate
0.51
-
ADPglucose
-
synthase II, presence of citrate
0.81
-
ADPglucose
-
-
0.97
-
ADPglucose
-
synthase I, presence of citrate
1.3
-
ADPglucose
-
granule bound starch synthase I, 5 mg/ml amylopectin
2.5
-
ADPglucose
-
assay in water or 85% isopropanol
0.75
-
Amylopectin
Zea saccharata
-
-
0.000272
-
dADPglucose
-
-
0.000864
-
glycogen
-
Arthrobacter glycogen
0.077
-
maltose
-
-
0.015
-
maltotriose
-
-
15.3
-
maltotriose
-
recombinant granule-bound starch synthase I
1.1
-
phytoglycogen
Zea saccharata
-
-
-
2.7
-
UDPglucose
-
-
16.6
-
maltotriose
Zea saccharata
-
-
additional information
-
additional information
-
amylopectin: 0.19-0.79 mg/ml, value depends on isozyme and presence of citrate
-
additional information
-
additional information
-
amylopectin: 0.16 mg/ml, rabbit liver glycogen: 1.16 mg/ml
-
additional information
-
additional information
-
0.002-1.5 mg/ml, value depends on isozyme and presence of citrate
-
additional information
-
additional information
-
E. coli B glycogen: 0.274 mg/ml, rabbit liver glycogen: 0.298 mg/ml, soluble potato amylose: 0.833 mg/ml
-
additional information
-
additional information
-
influence of citrate on values for primed and unprimed reaction
-
additional information
-
additional information
-
amylose: 0.02-0.06 mg/ml, isoenzymes I, II and IV, amylopectin: 0.03-0.05 mg/ml, isoenzymes I, II and IV, rabbit liver glycogen: 0.8-1.02 mg/ml, isoenzymes I, II and IV, oyster glycogen: 1.18-6.66 mg/ml, isoenzymes I-IV, amylopectin beta-limit dextrin: 0.02-0.22 mg/ml, isoenzymes I-IV, glycogen E. coli beta-limit dextrin: 1.0-2.0 mg/ml, isoenzymes I-IV
-
additional information
-
additional information
-
-
-
additional information
-
additional information
Zea saccharata
-
-
-
additional information
-
additional information
-
-
-
additional information
-
additional information
-
recombinant starch synthase I, amylopectin: 0.24 mg/ml, glycogen: 0.041 mg/ml
-
additional information
-
additional information
-
recombinant starch synthase IIa, amylopectin: 0.16 mg/ml, glycogen: 0.14 mg/ml, recombinant starch synthase IIb, amylopectin: 0.32 mg/ml, glycogen: 0.34 mg/ml
-
additional information
-
additional information
-
granule-bound starch synthase I, amylpectin: 10 mg/ml, starch synthase II, amylopectin: 0.79 mg/ml
-
additional information
-
additional information
-
recombinant starch synthase II, amylopectin: 4.6 mg/ml
-
additional information
-
additional information
-
-
-
additional information
-
additional information
-
starch synthase I, amylopectin: 0.08 mg/ml in the presence of citrate, 0.13 mg/ml in the absence of citrate, glycogen: 0.043 mg/ml in the presence of citrate, 12.8 mg/ml in the absence of citrate
-
additional information
-
additional information
-
Km-values for amylopectin: 0.2 mg/ml for wild-type enzyme, 0.53 mg/ml for mutant enzyme K193R, 0.13 mg/ml for mutant enzyme K193Q, 0.72 mg/ml for mutant enzyme K193E. Km-values for glycogen: 0.17 mg/ml for wild-type enzyme, 0.68 mg/ml for mutant enzyme K193R, 0.11 mg/ml for mutant enzyme K193Q, 0.53 mg/ml for mutant enzyme K193E
-
additional information
-
additional information
A4F2M4, -
Km-value for amylopectin is 2.4 mg/ml, KM-value for glycogen is 8.7 mg/ml
-
additional information
-
additional information
-
kinetics, overview
-
TURNOVER NUMBER [1/s]
TURNOVER NUMBER MAXIMUM[1/s]
SUBSTRATE
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
IMAGE
235
-
ADP-glucose
A4F2M4, -
pH 8.0, 30C, at 10 mg/ml amylopectin
333
-
ADP-glucose
A4F2M4, -
pH 8.0, 30C, at 10 mg/ml glycogen
235
-
Amylopectin
A4F2M4, -
pH 8.0, 30C
412
-
glycogen
A4F2M4, -
pH 8.0, 30C
Ki VALUE [mM]
Ki VALUE [mM] Maximum
INHIBITOR
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
IMAGE
0.38
-
D-glucono-1,5-lactone
-
-
SPECIFIC ACTIVITY [µmol/min/mg]
SPECIFIC ACTIVITY MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
0.026
-
-
in the presence of 0.5 mg glycogen primer and 500 mM sodium citrate
0.032
-
-
primed reaction, isoenzyme I
0.033
-
-
glycogen synthase I
0.039
-
-
glycogen synthase II
0.06
-
-
unprimed reaction in the presence of 500 mM citrate, recombinant starch synthase I
0.106
-
-
primed reaction, isoenzyme IV
0.118
-
-
primed reaction, isoenzyme III
0.28
-
-
unprimed reaction, isoenzyme III
0.338
-
-
primed reaction, isoenzyme II
0.93
-
-
unprimed reaction
1.1
-
-
unprimed reaction, synthase I
2.3
-
-
primed reaction, synthase I
3
-
-
primed reaction
12.2
-
-
primed reaction, recombinant starch synthase I
15.87
-
-
-
65.47
-
Zea saccharata
-
-
494
-
-
glycogen synthase I
505
-
-
glcogen synthase II
pH OPTIMUM
pH MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
7
10.3
-
starch synthases IIa and Iib, sharp decline in activity below pH 7.0
7
-
-
starch synthase II, 75% of maximal activity at pH 6.5
7.5
8.5
-
isoenzymes I-IV
8
10.3
-
starch synthase II, sharp decline in activity below pH 7.0
8
-
-
starch synthase I, 34% of maximal activity at pH 6.5
8.3
-
Zea saccharata
-
-
8.5
-
-
-
8.5
-
A4F2M4, -
-
pH RANGE
pH RANGE MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
6.5
9.7
Zea saccharata
-
less than half-maximal activity above and below
TEMPERATURE OPTIMUM
TEMPERATURE OPTIMUM MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
24
30
Zea saccharata
-
65% activity at 37C
30
-
-
4 isozymes, primed reaction
37
-
-
unprimed synthase activity of isoenzyme III
37
-
-
starch synthase II, 60% of maximal activity at 23C
40
50
-
recombinant starch synthase I in the presence of citrate
40
-
-
starch synthase IIb, in the presence of 500 mM citrate
42
-
-
starch synthase I, 15% of maximal activity at 23C
45
-
-
starch synthase IIa, in the presence of 500 mM citrate
50
-
-
-
TEMPERATURE RANGE
TEMPERATURE MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
SOURCE TISSUE
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
SOURCE
-
starch synthase I and II
Manually annotated by BRENDA team
-
SSIIa protein is present even in Nipponbare endosperm but is not associated with starch granules at the milky stage of endosperm
Manually annotated by BRENDA team
-
activity of starch synthase in the grains follows single-peak curves with the peaks on 24-31 days after pollination. The accumulation rates of starch and its components reach their peaks on 25-32 days after pollination. There is significant positive correlation between adenosine diphosphoglucose diphosphorylase, soluble starch synthase, and starch granule-bound synthase activities
Manually annotated by BRENDA team
-
transcripts for PvSSI and PvSSII-1
Manually annotated by BRENDA team
-
OsGBSSII is mainly expressed in leaves
Manually annotated by BRENDA team
-
more SSII protein is found in aged leaves than in leaves of other stages
Manually annotated by BRENDA team
-
more SSSI transcript is expressed in leaves than in tubers. Two forms of SSSI, i.e., 72000 Da and 66000 Da, exist in leaves
Manually annotated by BRENDA team
Q6UBQ7, Q84VC7, Q8L8G9, Q8W1P1
OsSSIII-1 is mainly expressed in endosperm; OsSSIV-2 s mainly expressed in endosperm
Manually annotated by BRENDA team
A9QXF0
-
Manually annotated by BRENDA team
-
granule-bound starch synthase II
Manually annotated by BRENDA team
A9QXF0
-
Manually annotated by BRENDA team
Zea saccharata
-
-
Manually annotated by BRENDA team
-
transcripts for PvSSI and PvSSII-1 accumulate in developing seeds in the early stage
Manually annotated by BRENDA team
-
the SSI activity of an indica rice variety, Kasalath, is significantly lower than that of a japonica rice variety, Nipponbare. The low activity in Kasalath is maintained during seed development The low expression of SSI in Kasalath is controlled at the transcription levels of SSI mRNA
Manually annotated by BRENDA team
Q6UBQ7, Q84VC7, Q8L8G9, Q8W1P1
OsSSIII-2 is mainly expressed in endosperm; OsSSIV-1 is mainly expressed in endosperm
Manually annotated by BRENDA team
-
the barley shrunken grain mutant M292 has a novel high-amylose starch phenotype caused by a mutation in the starch synthase IIa gene (SsIIa) located at the starch excess-6 (sex6) locus on chromosome 7H of barley. The loss of SSIIa enzyme activity leads to a decrease in amylopectin synthesis to less than 20% of the levels found in wild-type grains
Manually annotated by BRENDA team
-
the content of amylose in SA418 grain is higher than Tainung 67 and SA419 grains throughout the entire grain filling period, possibly due to its superiority to synthesize amylose through GBSS
Manually annotated by BRENDA team
-
raw strach granules of mature seed
Manually annotated by BRENDA team
-
more transcript and protein are accumulated in tubers of 597 g fresh weight, that is, a stage of rapid starch synthesis, than tubers of other stages. Found in both soluble and granule bound portions of tuber extracts
Manually annotated by BRENDA team
-
more transcript and protein are found in tubers of 597 fresh weight than in smaller or larger ones. Only the 66000 Da form of SSSI exists in tuber
Manually annotated by BRENDA team
LOCALIZATION
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
GeneOntology No.
LITERATURE
SOURCE
-, Q2HWR3
bound to, low CO2 level up-regulates GBSS biosynthesis at the transcriptional level
Manually annotated by BRENDA team
Parachlorella kessleri 11 h
-
bound to, low CO2 level up-regulates GBSS biosynthesis at the transcriptional level
-
Manually annotated by BRENDA team
Zea saccharata
-
-
-
Manually annotated by BRENDA team
-
starch synthase II, soluble and granule-bound
-
Manually annotated by BRENDA team
Arthrobacter sp. NRRL B1973
-
-
-
-
Manually annotated by BRENDA team
-
starch synthase II, soluble and granule-bound
Manually annotated by BRENDA team
-
starch synthase II is exclusively bound to
Manually annotated by BRENDA team
Arthrobacter sp. NRRL B1973
-
-
-
Manually annotated by BRENDA team
PDB
SCOP
CATH
ORGANISM
Escherichia coli (strain K12)
Escherichia coli (strain K12)
Escherichia coli (strain K12)
Escherichia coli (strain K12)
Escherichia coli (strain K12)
Escherichia coli O1:K1 / APEC
Escherichia coli O6:K15:H31 (strain 536 / UPEC)
Pyrococcus abyssi (strain GE5 / Orsay)
Pyrococcus abyssi (strain GE5 / Orsay)
Pyrococcus abyssi (strain GE5 / Orsay)
Pyrococcus abyssi (strain GE5 / Orsay)
Rhizobium radiobacter
Rhizobium radiobacter
MOLECULAR WEIGHT
MOLECULAR WEIGHT MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
69000
-
-
synthase II, gel filtration
70000
-
-
gel filtration
92700
-
-
sucrose density gradient centrifugation
110000
-
-
synthase I, gel filtration
SUBUNITS
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
?
-
x * 60000, synthase I, x * 77000, synthase II, SDS-PAGE
?
-
x * 60000, SDS-PAGE
?
-
x * 139000, deduced from nucleotide sequence
?
-
x * 53000 + x * 32000, SDS-PAGE
?
C9K223
x * 67000, SDS-PAGE
?
-
x * 58000, SDS-PAGE
?
A9YWT9
x * 82306, calculated
?
A9QXF0
x * 87096, calculated
?
Q9HH97
x * 60000, SDS-PAGE
?
-
x * 60000, SDS-PAGE
-
decamer
-
10 * 12000, synthase I, SDS-PAGE
dimer
-
2 * 49000, SDS-PAGE
dimer
-
2 * 11500, SDS-PAGE, enzyme may exist as dimer and hexamer
dimer
-
SDS-PAGE and gel filtration, quaternary structure determination, recombinant enzyme
oligomer
-
enzyme is active in at least 2 oligomeric forms, bands in SDS-PAGE of 11500 Da, 20000 Da, 35000 Da, 50000 Da, 68000 Da, and in gel filtration of 22000 Da and 67000 Da
hexamer
-
6 * 12000, synthase II, SDS-PAGE
additional information
-
possibly a monomer of 70000 Da or a dimer of 2 * 38000 Da
additional information
-
minimum granule-bound starch synthase I protein required for catalysis and starch affinity compromises 52000 Da
additional information
-
enzyme contains an N-terminal region, including three in-tandem starch-binding domains, followed by a C-terminal catalytic domain. The D(316-344) and D(495-535) regions in the D2 and D3 domains, respectively, but not the individual starch-binding domains, are involved in the interaction with the catalytic domain. Residues W366 and Y394 in the D2 domain are important in starch binding. Residue W366 is key to the apparent affinity for the polysaccharide substrate of starch synthase III
additional information
O64923
mutations that eliminate any one of starch synthases SSIII, SSIIa, and starch branching enzymes SBEIIa, and SBEIIb also prevent the others from assembling into a high molecular mass form of approximately 670 kDa. SSIII, SSIIa, SBEIIa, and SBEIIb most likely all exist together in the same complex. SSIIa, SBEIIb, and SBEIIa, but not SSIII, are also interdependent for assembly into a complex of approximately 300 kDa. SSIII, SSIIa, SBEIIa, and SBEIIb copurifiy through successive chromatography steps, and SBEIIa, SBEIIb, and SSIIa coimmunoprecipitate with SSIII in a phosphorylation-dependent manner. Pyruvate orthophosphate dikinase and sucrose synthase isoform SUS-SH1 require SSIII, SSIIa, SBEIIa, and SBEIIb for assembly into the 670 kDa complex
additional information
-
isoform IIb assembles to trimer with starch synthase I and starch synthase IIa. Starch synthase IIa is at the core of the complex, interacting with starch synthase I and starch branching enzyme IIb, which do not interact directly with each other
POSTTRANSLATIONAL MODIFICATION
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
proteolytic modification
C9K223
sequence contains a transit peptide of 77 amino acids
glycoprotein
-
glycogen synthase II, 1.7% carbohydrate may be due to an endogenous primer
proteolytic modification
A9YWT9
sequence contains a putative transit peptide of 64 amino acids
proteolytic modification
A9QXF0
sequence contains a putative transit peptide of 69 amino acids
Crystallization/COMMENTARY
ORGANISM
UNIPROT ACCESSION NO.
LITERATURE
cocrystallization of the inactive glycogen synthase mutant E377A with substrate ADPGlc and cocrystallization of wild-type glycogen synthase with substrate ADPGlc and the glucan acceptor mimic 4-(2-hydroxyethyl)piperazine-1-(2-hydroxypropane)sulfonic acid, i.e. HEPPSO produces a closed form of glycogen synthase and suggests that domain-domain closure accompanies glycogen synthesis. Four bound oligosaccharides are observed, G6a in the interdomain cleft and G6b, G6c, and G6d on the N-terminal domain surface. Extending from the center of the enzyme to the interdomain cleft opening, G6a mostly interacts with the highly conserved N-terminal domain residues lining the cleft of glycogen synthase. The surface-bound oligosaccharides G6c and G6d have less interaction with enzyme and exhibit a more curled, helixlike structural arrangement
-
structure of the wild-type enzyme bound to ADP and glucose reveals a 15.2 overall domain-domain closure. The main chain carbonyl group of His-161, Arg-300, and Lys-305 are suggested to act as critical catalytic residues in the transglycosylation. Glu-377 is found on the-face of the glucose and plays an electrostatic role in the active site and as a glucose ring locator. In the mutant E377A-ADP-4-(2-hydroxyethyl)piperazine-1-(2-hydroxypropane)sulfonic acid complex the glucose moiety is either absent or disordered in the active site
-
pH STABILITY
pH STABILITY MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
6.5
10
A4F2M4, -
stable
TEMPERATURE STABILITY
TEMPERATURE STABILITY MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
15
-
-
stable at
25
-
-
stable at
25
-
-
granule-bound starch synthase I, loss of 35% activity after 1 h
35
-
-
inactivation
35
-
-
starch synthase II, loss of 6% activity after 1 h
40
-
Zea saccharata
-
10 min, 78% loss of activity
40
-
-
granule-bound starch synthase I, complete inactivation after 1 h, starch synthase II, loss of 52% activity after 1 h
42
-
-
starch synthase I, no loss of activity after 30 min, starch synthase II, loss of more than 50% activity after 30 min
45
-
A4F2M4, -
stable below
50
-
-
stable up to
50
-
Zea saccharata
-
1 min, 75% loss of activity
62
-
Zea saccharata
-
inactivation at
ORGANIC SOLVENT
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
additional information
-
more than 70% isopropanol activates, 85% n-propanol activates
STORAGE STABILITY
ORGANISM
UNIPROT ACCESSION NO.
LITERATURE
-85C, at least 1 year
-
0-4C, ammonium sulfate precipitate
-
-20C, at least 4 months, no loss of activity
-
4C, at least 2 weeks, no loss of activity
-
addition of 0.04% (w/v) polyvinyl alcohol 50 K and 1 mM dithiothreitol to the glycine buffer, pH 8.4, leads to long-term stability and
-
higher yields of both starch synthase and starch branching enzyme, due to activation of inactive enzymes
-
-20C, 6 months, 50% loss of activity
-
0C, 1 month, 30% loss of activity
-
-80C, purified His-tagged enzyme, in 20 mM triethanolamine-HCl, pH 8.0, and 20% v/v glycerol, stable for at least 6 months
-
-70C, 50 mM Tris/acetate buffer, pH 7.5, 2.5 mM DTT, 10 mM EDTA, 5% w/v sucrose
-
-10C, fraction V, unstable
Zea saccharata
-
-15C, fraction IV, 6 months
Zea saccharata
-
Purification/COMMENTARY
ORGANISM
UNIPROT ACCESSION NO.
LITERATURE
recombiantly expressed catalytic C-terminal domain (SSIII-CD)
Q1WAB7
ammonium sulfate, calcium phosphate gel, DEAE-cellulose
-
recombinant enzyme
-
2 isozymes, DEAE-cellulose, 4-aminobutyl-Sepharose, Bio-Gel P200
-
4 isoenzymes, ammonium sulfate, DEAE-cellulose
-
2 isozymes
-
2 isoforms, DEAE-Sepharose, ammonium sulfate, Blue Sepharose, omega-aminobutyl agarose, Mono Q
-
ammonium sulfate, maltotriose-Sepharose, DEAE-Toyopearl, Sepharose Cl-6B
-
large scale purification from white potato tuber
-
starch synthase III, ammonium sulfate, DEAE-Sepharose, Blue Sepharose, Mono Q, cyclohexaamylose
-
4 isoenzymes, ammonium sulfate, DEAE-cellulose
-
ammonium sulfate, DEAE-cellulose, ADP-hexanoamine-Sepharose 4B
-
recombinant N-terminally His-tagged GSase from Escherichia coli strain BL21(DE3) or Top10 by nickel affinity chromatography and dialysis
-
partial, from raw strach granules of mature seed
-
2 isozymes
-
6 isozymes
-
ammonium sulfate, DEAE-cellulose
-
ammonium sulfate, DEAE-cellulose, aminobutyl-Sepharose, ADP-hexanolamine-Sepharose, aminopropyl-Sepharose
-
recombinant starch synthase I, ammonium sulfate, amylose column, Mono Q
-
starch synthases I and II, Q-Sepharose, Mono Q, amylose-agarose
-
wild-type and mutant enzymes expressed in Escherichia coli
-
-
Zea saccharata
-
ammonium sulfate, DEAE-cellulose
Zea saccharata
-
Cloned/COMMENTARY
ORGANISM
UNIPROT ACCESSION NO.
LITERATURE
construction of recombinant full length and truncated isoforms of SSIII, lacking one, two, or three starch-binding domains, and recombinant proteins, containing three, two, or one starch-binding domains, to investigate the role of these domains in enzyme activity
Q9SAA5
the catalytic C-terminal domain (SSIII-CD) of is cloned and expressed in Escherichia coli. SSIII-CD fully complements the production of glycogen by an Agrobacterium tumefaciens glycogen synthase null mutant, suggesting that this truncated isoform restores in vivo de novo synthesis of bacterial glycogen
Q1WAB7
expression in Escherichia coli
-
expression in Escherichia coli
-
cloning and sequencing of cDNA encoding SSIIa of japonica and indica rice cultivars, expression in Escherichia coli
-
expression in Escherichia coli
-
expression of OsSSIII-1 in Escherichia coli; expression of OsSSIII-2 in Escherichia coli; expression of OsSSIV-1 in Escherichia coli; expression of OsSSIV-2 in Escherichia coli
Q6UBQ7, Q84VC7, Q8L8G9, Q8W1P1
expression of PvSSI and PvSSII-1 in Escherichia coli
-
three recombinant proteins are constructed: putative mature recombinant SSIII (rPvSSII), recombinant kidney bean SSIII N-domain (rPvSSIII-N), and recombinant kidney bean SSIII C-domain (rPvSSIII-C)
A4F2M4, -
expression of granule-bound starch synthase I in Escherichia coli
-
expression of starch synthase II in Escherichia coli and potato
-
cloning of starch synthase III cDNA
-
expression of granule-bound starch synthase I and soluble starch synthase II in Escherichia coli
-
expression of granule-bound starch synthase in Escherichia coli
-
expression of N-terminally His-tagged GSase in Escherichia coli strain BL21(DE3) or Top10
-
expression of C-terminal domain in Escherichia coli
A9YWT9
expression in Escherichia coli
-
expression of C-terminal domain in Escherichia coli
A9QXF0
expression of full length and truncated starch synthase IIa and IIb in Escherichia coli
-
expression of full-length and truncated enzyme in Escherichia coli
-
EXPRESSION
ORGANISM
UNIPROT ACCESSION NO.
LITERATURE
expression reaches maximum level at the middle developmental age of endosperm after pollination
A9YWT9
expression reaches maximum level at the middle developmental age of endosperm after pollination
A9QXF0
ENGINEERING
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
W366A
-
mutation in starch-binding domains, 3fold decrease in affinity to starch
W366A/Y394A
-
mutation in starch-binding domains, significant decrease in affinity to starch
Y394A
-
mutation in starch-binding domains, 2fold decrease in affinity to starch
C7S/C409S
-
exhibits comparable specific activity and apparent affinity for ADP-Glc to wild-type. Use as alternative in crystallization trials to avoid aggregation
E377A
-
inactive, crystallization data
E377A
-
crystallization data, in the mutant E377A-ADP-4-(2-hydroxyethyl)piperazine-1-(2-hydroxypropane)sulfonic acid complex the glucose moiety is either absent or disordered in the active site
K193E
-
mutation does not alter the binding of ADP-glucose, Km-value for amylopectin is 3.6fold higher than the wild-type value, KM-value for glycogen is 3.2fold lower than the wild-type value
K193Q
-
mutation does not alter the binding of ADP-glucose, Km-value for amylopectin is 1.5fold lower than the wild-type value, KM-value for glycogen is 15.5fold lower than the wild-type value
K193R
-
mutation does not alter the binding of ADP-glucose, Km-value for amylopectin is 2.6fold higher than the wild-type value, KM-value for glycogen is 2.5fold lower than the wild-type value
APPLICATION
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
nutrition
-
analysis of the natural variations of isoforms granule-bound starch synthase GBSSI, starch synthases SSI and SSIIa and their effect on starch properties and eating quality of rice. Rice with the combinantion of the Wx allele for GBSSI and the alk allele for SSIIa has soft and sticky texture both after cooking and after storage. Variation of SSI alleles hardly affects the eating quality
agriculture
-
incubation of excised developing grains of ambient grown plants at 15C, 25C, 35C and 45C. Elevated temperature does not lead to a decrease in grain growth. High temperature tolerance is associated with higher catalytic efficiency of soluble starch synthase at elevated temperature and higher content of HSP 100; incubation of excised developing grains of ambient grown plants at 15C, 25C, 35C and 45C. Elevated temperature leads to a significant decrease in grain growth
agriculture
-
in a cultivar with a high starch content, the starch accumulation rate and activities of sucrose synthase, ADP-glucose dihosphorylase, soluble starch synthase, granule-bound starch synthase, and starch branching enzyme are significantly higher than those in a cultivar with a low starch content. Plants of the cultivar with a high starch content maintain the higher starch accumulation rate and greater activities of related enzymes during mid and late grain filling stages
agriculture
-
activity of starch synthase in the grains follows single-peak curves with the peaks on 24-31 days after pollination. The accumulation rates of starch and its components reach their peaks on 25-32 days after pollination. There is significant positive correlation between adenosine diphosphoglucose diphosphorylase, soluble starch synthase, and starch granule-bound synthase activities