Information on EC 2.4.2.14 - amidophosphoribosyltransferase

New: Word Map on EC 2.4.2.14
Please wait a moment until all data is loaded. This message will disappear when all data is loaded.
Specify your search results
Mark a special word or phrase in this record:
Search Reference ID:
Select one or more organisms in this record:
Show additional data
Do not include text mining results
Include (text mining) results (more...)
Include results (AMENDA + additional results, but less precise; more...)


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

EC NUMBER
COMMENTARY hide
2.4.2.14
-
RECOMMENDED NAME
GeneOntology No.
amidophosphoribosyltransferase
REACTION
REACTION DIAGRAM
COMMENTARY hide
ORGANISM
UNIPROT
LITERATURE
5-phospho-beta-D-ribosylamine + diphosphate + L-glutamate = L-glutamine + 5-phospho-alpha-D-ribose 1-diphosphate + H2O
show the reaction diagram
REACTION TYPE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
amino group transfer
PATHWAY
BRENDA Link
KEGG Link
MetaCyc Link
4-amino-2-methyl-5-diphosphomethylpyrimidine biosynthesis (yeast)
-
-
5-aminoimidazole ribonucleotide biosynthesis I
-
-
5-aminoimidazole ribonucleotide biosynthesis II
-
-
Alanine, aspartate and glutamate metabolism
-
-
Biosynthesis of antibiotics
-
-
Biosynthesis of secondary metabolites
-
-
Metabolic pathways
-
-
purine metabolism
-
-
Purine metabolism
-
-
superpathway of 5-aminoimidazole ribonucleotide biosynthesis
-
-
SYSTEMATIC NAME
IUBMB Comments
5-phospho-beta-D-ribosylamine:diphosphate phospho-alpha-D-ribosyltransferase (glutamate-amidating)
-
CAS REGISTRY NUMBER
COMMENTARY hide
9031-82-7
-
ORGANISM
COMMENTARY hide
LITERATURE
UNIPROT
SEQUENCE DB
SOURCE
-
-
-
Manually annotated by BRENDA team
brine shrimp, activity increases 7fold during early larval development in 2 d old Artemia
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
-
UniProt
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
no activity in Escherichia coli
strain DM1293, lacking purF gene product, purF77::TN10
-
-
Manually annotated by BRENDA team
no activity in Escherichia coli DM1293
strain DM1293, lacking purF gene product, purF77::TN10
-
-
Manually annotated by BRENDA team
no activity in Salmonella sp.
Salmonella enterica strain DM1936, lacking purF gene product, purF2085
-
-
Manually annotated by BRENDA team
wild type strain 972h- and mutant strain ade 2h- devoid of adenylosuccinate synthase
-
-
Manually annotated by BRENDA team
GENERAL INFORMATION
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
physiological function
SUBSTRATE
PRODUCT                       
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate) hide
LITERATURE
(Substrate)
COMMENTARY
(Product) hide
LITERATURE
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
L-glutamine + 5-phospho-alpha-D-ribose 1-diphosphate + H2O
5-phospho-beta-D-ribosylamine + diphosphate + L-glutamate
show the reaction diagram
L-glutamine + 5-phospho-alpha-D-ribose 1-diphosphate + H2O
5-phospho-beta-D-ribosylamine + L-glutamate + diphosphate
show the reaction diagram
L-glutamine + 5-phospho-alpha-D-ribose 1-diphosphate + H2O
L-glutamate + 5-phospho-beta-D-ribosylamine + diphosphate
show the reaction diagram
L-glutamine + H2O
L-glutamate + NH3
show the reaction diagram
NH3 + 5-phospho-alpha-D-ribose 1-diphosphate + H2O
5-phospho-beta-D-ribosylamine + diphosphate
show the reaction diagram
phosphoribosylanthranilate
indoleglycerol phosphate + CO2 + H2O
show the reaction diagram
5 M PurF mutant I198V or variant 1-04, in presence of 0.5 mM beta-mercaptoethanol, pH 8.6, 23 C, 16 h
Amadori rearrangement of aminoaldose (phosphoribosylanthranilate) to aminoketose (indoleglycerol phosphate)
-
?
additional information
?
-
NATURAL SUBSTRATES
NATURAL PRODUCTS
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate) hide
LITERATURE
(Substrate)
COMMENTARY
(Product) hide
LITERATURE
(Product)
REVERSIBILITY
r=reversible
ir=irreversible
?=not specified
L-glutamine + 5-phospho-alpha-D-ribose 1-diphosphate + H2O
5-phospho-beta-D-ribosylamine + diphosphate + L-glutamate
show the reaction diagram
L-glutamine + 5-phospho-alpha-D-ribose 1-diphosphate + H2O
L-glutamate + 5-phospho-beta-D-ribosylamine + diphosphate
show the reaction diagram
METALS and IONS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
Ca2+
-
activation, approx. 15% as effective as Mg2+ or Mn2+
Co2+
-
activation, approx. 40% as effective as Mg2+ or Mn2+
Mn2+
-
required, equally effective as Mg2+
additional information
INHIBITORS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
1-alpha-diphosphoryl-2-alpha,3-alpha-dihydroxy-4-beta-cyclopentane-methanol-5-phosphate
-
competitive vs. 5-phospho-alpha-D-ribose 1-diphosphate in wild-type and P410W mutant, competition for the amidotransferase C site
2-amino-4-oxo-5-chloropentanoate
-
approx. 80% inactivation of NH3-dependent activity after 30 min
5',5'-P1,P4-diguanosine tetraphosphate
-
IC50: 0.4 mM, 2 mM, approx. 80% inhibition
5'-p-fluorosulfonylbenzoyladenosine
-
inactivation follows pseudo-first order kinetic, AMP, GMP and 5-phospho-alpha-D-ribose 1-diphosphate protect
6-diazo-5-oxo-L-norleucine
6-iodopurine
-
5 mM, 39% inhibition
6-mercaptopurine ribonucleotide
-
5 mM, 64% inhibition
adenine nucleotide
maximal inhibition by combination of adenine nucleotides (in total 10 mM), inhibitory effect of single nucleotides (5 mM) increases in the order AMP, ATP, ADP
allopurinol ribonucleotide
-
5 mM, 68% inhibition
azaserine
-
competitive vs. glutamine, inactivation half-life: 12 min
CMP
-
5 mM, 22% inhibition
DAS734
phenyltriazole acetic acid herbicide, [5-(4-chlorophenyl)-1-isopropyl-1H-[1,2,4]triazol-3-yl]-acetic acid, inhibits Arabidopsis root growth by 50% at 200 nM, phytotoxicity can be alleviated by addition of adenine, no inhibitory effect on Escherichia coli; phenyltriazole acetic acid herbicide, [5-(4-chlorophenyl)-1-isopropyl-1H-[1,2,4]triazol-3-yl]-acetic acid, non-competitive with respect to L-glutamine with slow, tight-binding behavior, inhibits Arabidopsis root growth by 50% at 200 nM, phytotoxicity can be alleviated by addition of adenine, no inhibitory effect on Escherichia coli
dCMP
-
5 mM, 26% inhibition
diphosphate
-
uncompetitive vs. 5-phospho-alpha-D-ribose 1-diphosphate
glutamate
-
competitive vs. glutamate
IDP
-
5 mM, 29% inhibition
iodoacetamide
-
approx. 60% inactivation of amidotransferase activity after 30 min, very weak inactivation of NH3-dependent activity
methyl-dCMP
-
5 mM, 47% inhibition
N3-AMP
-
1.2-1.4 mM, 50% inhibition, AMP and GMP protect
NH3
-
inhibition of amidotransferase activity
NH4+
-
competitive vs. glutamine
OMP
-
5 mM, 25% inhibition
p-mercuribenzoate
-
0.001 mM, complete inhibition
phosphate
piritrexim
-
noncompetitive vs. 5-phospho-alpha-D-ribose 1-diphosphate, binds with positive cooperativity at 2 allosteric sites of an inactive dimer
purine nucleotide
allosteric feedback inhibition by end products of the purine biosynthesis pathway, act on the PRPP domain
-
TMP
-
5 mM, 42% inhibition
TTP
-
5 mM, 12% inhibition
UDP
-
5 mM, 19% inhibition
UMP
-
5 mM, 25% inhibition
UTP
-
5 mM, 16% inhibition
XDP
-
5 mM, 27% inhibition
XTP
-
5 mM, 44% inhibition
additional information
ACTIVATING COMPOUND
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
Mg-phosphoribosyldiphosphate
phosphoribosyl-5-phosphate
-
3-4fold activation of glutaminase activity in the presence of phosphate or diphosphate
additional information
KM VALUE [mM]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
0.031 - 0.87
5-phospho-alpha-D-ribose 1-diphosphate
193
glutamine
-
5-phospho-alpha-D-ribose 1-diphosphate-independent glutamine hydrolysis
0.1 - 236
L-glutamine
0.65
Mg2+
-
-
7.34 - 16
NH3
16
NH4+
-
-
additional information
additional information
TURNOVER NUMBER [1/s]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
additional information
phosphoribosylanthranilate
Escherichia coli K-12
P0AG16
mutant I198V, modestly higher rate than spontaneous substrate hydrolysis of <1/h; variant 1-04, 25 to 30-fold more active than mutant I198V but 2.3*10(7)-fold less efficient than phosphoribosylanthranilate isomerase; variant 1-04, conversion of 5.5% of available substrate, 22 turnovers per active site
Ki VALUE [mM]
INHIBITOR
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
0.053 - 0.058
1-alpha-diphosphoryl-2-alpha,3-alpha-dihydroxy-4-beta-cyclopentane-methanol-5-phosphate
0.39
5'-p-fluorosulfonylbenzoyladenosine
-
-
0.0034
6-diazo-5-oxo-L-norleucine
-
-
0.038 - 0.64
ADP
-
-
0.04 - 2.5
AMP
0.031 - 1.1
ATP
-
-
4
azaserine
-
-
0.65
diphosphate
-
-
0.38 - 5.4
GDP
-
-
30
glutamate
-
-
0.086 - 0.35
GMP
-
-
0.18 - 3.5
IMP
-
-
3.3
NH3
-
-
16
NH4+
-
-
0.066
piritrexim
-
-
1.2
XMP
-
-
IC50 VALUE [mM]
INHIBITOR
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
0.4
5',5'-P1,P4-diguanosine tetraphosphate
Artemia sp.
-
IC50: 0.4 mM, 2 mM, approx. 80% inhibition
0.0002
DAS734
Arabidopsis thaliana
Q9SI61, Q9STG9, Q9T0J5
10 min preincubation of recombinant enzyme with inhibitor leads to maximum inhibition, slow but reversible binding; cell extracts of recombinant AtGPRAT3 expressing Escherichia coli
7.9
GMP
Aquifex aeolicus
-
IC50: 7.9 mM
additional information
DAS734
SPECIFIC ACTIVITY [µmol/min/mg]
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
0.001
-
L-glutamine
0.00125 - 0.0014
-
-
0.00297
-
NH3
0.0055
-
-
3
-
wild-type, pH 8.0, 37C
15.6
-
-
additional information
-
assay method to measure both amidotransferase and aminotransferase activity
pH OPTIMUM
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
6 - 8
-
broad, phosphate buffer
6.5 - 8.5
-
glutaminase activity
6.5
-
imidazole/HCl buffer
6.5 - 8.5
-
broad, Tris or phosphate buffer, constant activity
6.6 - 7.7
-
broad, amidotransferase activity, phosphate buffer
6.8 - 7.4
-
Tris/HCl buffer preferred
7.8 - 8.6
-
broad, amidotransferase activity, Tris/HCl buffer
8.5
-
aminotransferase activity, Tris buffer
pH RANGE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
6 - 10
-
approx. 70% of maximal activity between pH 6 and pH 10
7 - 9
-
stable enzyme, approx. 65% and unstable enzyme approx. 70% of maximal activity at pH 7, stable enzyme, approx. 75% and unstable enzyme approx. 65% of maximal activity at pH 9
TEMPERATURE OPTIMUM
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
38
-
assay at
90
-
both glutaminase and amidotransferase activity
SOURCE TISSUE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
SOURCE
-
adenocarcinoma 755
Manually annotated by BRENDA team
-
L1210 leukemia cells
Manually annotated by BRENDA team
-
diploid wild 2 line, tissue culture
Manually annotated by BRENDA team
-
-
Manually annotated by BRENDA team
LOCALIZATION
ORGANISM
UNIPROT
COMMENTARY hide
GeneOntology No.
LITERATURE
SOURCE
-
little or no activity in mitochondria or microsomes
Manually annotated by BRENDA team
PDB
SCOP
CATH
ORGANISM
UNIPROT
Bacillus subtilis (strain 168)
Bacillus subtilis (strain 168)
Escherichia coli (strain K12)
Escherichia coli (strain K12)
Escherichia coli (strain K12)
Escherichia coli (strain K12)
Escherichia coli (strain K12)
MOLECULAR WEIGHT
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
54000
SDS-PAGE analysis of the recombinant AtGPRAT2 expressed in Escherichia coli
93000
-
sucrose density gradient centrifugation, enzyme exists in equilibrium of tetrameric, dimeric and monomeric forms
102000
-
sedimentation equilibrium centrifugation, phosphate, phosphoribosyldiphosphate or purine mononucleotides influence the sedimentation profile
110000
-
ligand-induced alteration of sedimentation coefficient and Stokes radius, gel filtration or sedimentation equilibrium centrifugation
127000
-
liver small form
133000
-
placenta small form, large form is converted to small form by incubation with phosphoribosyldiphosphate
170000
-
placenta large form, in the presence of AMP or GMP
172000
-
sedimentation equilibrium centrifugation in the presence of phosphoribosyldiphosphate, the sedimentation profile is influenced by phosphate, phosphoribosyldiphosphate or purine mononucleotides
180000
-
mutant unstable enzyme, gel filtration
181000
-
sedimentation equilibrium centrifugation in the presence of phosphate, the sedimentation profile is influenced by phosphate, phosphoribosyldiphosphate or purine mononucleotides
185000
-
highly concentrated enzyme solution, sucrose density gradient centrifugation, enzyme exists in equilibrium of tetramer, dimer and monomeric forms, conversion of dimer to tetramer within 10fold increase in protein concentration
194000
-
sedimentation equilibrium centrifugation
195000
-
sucrose density gradient centrifugation
200000
215000
224000
-
gel filtration
270000
-
placenta, large form, small form is converted to large form by incubation with purine nucleotides, large form presumably catalytically inactive
292000
-
liver, large form
360000
-
wild-type stable enzyme, gel filtration
8000000
-
probably an aggregation of several purine synthetic activities, gel filtration
additional information
SUBUNITS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
Crystallization/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
when mapped onto the structure from Bacillus subtilis GPRAT (PDB: 1AO0), the site of mutation R264K lies within 10 A of the glutaminase site
crystal structure at 3.0 A
-
crystals of the ternary enzyme-ADP-GMP complex are grown in glass melting point capillaries by the microbath method, 20 mg/ml enzyme are incubated with 1 mM ADP, 1 mM GMP, and 5 mM MgCl2 and mixed with an equal volume of 24% polyethylene glycol 8000, 200 mM KCl, 50 mM N-(2-hydroxyethyl)piperazine-N'-3-propanesulfonic acid, pH 7.9, brown crystals emerge after 6-12 weeks
crystal structure in the absence of ligands at 2.0 A, and with bound AMP at 2.5 A
-
crystal structure of 6-diazo-5-oxonorleucine inactivated enzyme at 2.3 A resolution
-
TEMPERATURE STABILITY
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
37
-
glutaminase half-life: 25 h
48
-
wild-type, stable enzyme from cells of mid-exponential growth phase, t1/2: 34 min, from cells of stationary growth phase, t1/2: 2-5 min, mutant enzyme, t1/2: 2 min, in the presence of ADP or adenosine 3 min, and 4 min in the presence of IMP
80
-
glutaminase half-life: 65 min
additional information
-
AMP and GMP enhance thermal stability
GENERAL STABILITY
ORGANISM
UNIPROT
LITERATURE
2-mercaptoethanol stabilizes during purification
-
ADP or ADP and GMP, ratio 1/1, stabilize equilibrium between dimeric and tetrameric form
-
AMP or GMP stabilizes dimeric enzyme form
-
AMP stabilizes against inactivation by O2
-
freezing inactivates, not stabilized by 30% glycerol
-
GDP stabilizes tetrameric enzyme form
-
high concentrations of thiol reagents stabilize during purification
-
Mg2+ and phosphate are essential for stability
-
phosphoribosyldiphosphate and other nucleotides antagonize stabilizing effect of AMP
-
prolonged dialysis against distilled water leads to precipitation
-
stability profile depends on growth rate and growth phase of cell culture, PMSF improves stability
-
stable during all stages of purification provided thiols and oxygen are avoided
-
OXIDATION STABILITY
ORGANISM
UNIPROT
LITERATURE
amido- and aminotransferase activity is lost after exposure to oxygen
-
489754
anaerobic conditions stabilize
in vitro O2 oxidizes iron in the Fe-S cluster to the high spin ferric state and sulfur to a mixtur of S in thiocystine residues plus other unidentified products
-
489755
low concentrations of thiols e.g. dithiothreitol or 2-mercaptoethanol accelerate aerobic inactivation
-
489747
O2, rather than peroxide, superoxide, hydroxyl radical or singlet oxygen, inactivates, allosteric inhibitors, such as AMP, ADP, GMP or GDP modulate the rate of inactivation
-
489753
oxygen inactivates during purification
-
489747
oxygen sensitive enzyme
oxygen-labile in vivo and in vitro, AMP protects
-
489748
STORAGE STABILITY
ORGANISM
UNIPROT
LITERATURE
-20C or 4C, cell-free extract, overnight, more than 50% loss of activity
-
-20C, crude, more than 50% loss of activity overnight
-
2-mercaptoethanol and phosphoribosyldiphosphate stabilize during storage at 4C
-
2-mercaptoethanol stabilizes during storage
-
3C, crude mutant enzyme extract, inactivation overnight, partially purified mutant enzyme: inactivation within 72 h, PMSF stabilizes
-
3C, crude or partially purified wild-type enzyme, at least 72 h stable
-
4C, 25% loss of activity per day
-
4C, 50 mM phosphate bufer, pH 7.4, 5 mM MgCl2, 60 mM 2-mercaptoethanol, at least 4 weeks, no loss of activity
-
4C, in phosphate buffer, pH 7.4, 60 mM 2-mercaptoethanol and phosphoribosyldiphosphate, at least 10 days
-
4C, partially purified preparation in 50 mM phosphate buffer, pH 7.4, 5 mM Mg2+ and 60 mM 2-mercaptoethanol, at least 4 weeks
-
4C, phosphate buffer, 10 d, 40% loss of activity
-
phosphate stabilizes during storage
-
PMSF stabilizes during storage
-
storage in 25 mM Tris buffer inactivates with 26% or 4% residual activity after 6 or 10 days, respectively
-
Purification/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
ammonium sulfate, heat treatment, calcium phosphate gel, DEAE-cellulose; partial
-
ammonium sulfate, heat treatment, DEAE-Sepharose, Blue Dextran-Sepharose, hydroxylapatite
-
DEAE-cellulose, partial purification
-
from bacterial extracts by desalting on a Bio-Rad 10DG column in presence of 10 mM dithiothreitol, stored at -70C
heat treatment, acid precipitation, ammonium sulfate, ethanol, Sephadex G-150, DE-52
-
hexa-His-tagged mutant I198V and its variant 1-04 by metal affinity chromatography in presence of 1 mM beta-mercaptoethanol and 10% (v/v) glycerol, elution with 250 mM imidazole followed by dialysis
partial
partial, ATP-agarose affinity chromatography
-
protamine sulfate, DEAE-cellulose
-
recombinant enzyme
-
recombinant wild-type and P410W mutant enzyme
-
Sepharose CL-2B, glycerol gradient
-
streptomycin, ammonium sulfate, Sephadex g-200
-
Cloned/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
amplified from seedling cDNA library to encode 11-amino acid autoprocessing propeptide, N-terminal cysteine for an active enzyme and deleted chloroplast transit peptide, in pCR2.1TOPO for sequencing, in pET26b for expression in Escherichia coli BL21(DE3); amplified from seedling cDNA library to encode 11-amino acid autoprocessing propeptide, N-terminal cysteine for an active enzyme and deleted chloroplast transit peptide, in pCR2.1TOPO for sequencing, in pET26b for expression in Escherichia coli BL21(DE3); amplified from seedling cDNA library to encode 11-amino acid autoprocessing propeptide, N-terminal cysteine for an active enzyme and deleted chloroplast transit peptide, in pCR2.1TOPO for sequencing, in pET26b for expression in Escherichia coli BL21(DE3)
expression in Escherichia coli
expression of wild-type and K338Q/P422W mutant enzyme in amidophosphoribosyltransferase deficient CHO ade -A cells and in transgenic mice
-
expression of wild-type, Y74A, Y258A, Y258F, K326Q, Y329A, G331I, N351A and Y465A mutant enzyme in Escherichia coli
-
overexpression of wild-type and P410W mutant enzyme in Escherichia coli
-
used in gene replacment and complementation experiments
wildtype, mutant I198V and variants 1-04 and 2-02 of mutant I198V in pCA24N for expression as N-terminal hexa-His-tagged, C-terminal GFP-tagged proteins in Escherichia coli JMB9 DELTA TrpF (auxotrophic for tryptophan) and/or Escherichia coli KK8(pDM), mutant I198V in pCDF-1b for error-prone PCR based mutagenesis yielding variant 1-04
ENGINEERING
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
R264K
increased resistance to DAS734 with >500-fold higher IC50 compared to wild-type: no inhibition by 100 microM DAS734 and no effect on reaction time course, the same allosteric inhibition by adenine nucleotides as the wild-type, Arg-264 conserved in almost every GPRAT sequence
A417W
-
moderate resistance to inhibition by ATP or GPT
D310V
-
almost resistant to inhibition by ATP or GTP, low concentrations of ATP plus GTP activate
K333Q
-
almost resistant to inhibition by ATP or GTP, low concentrations of ATP plus GTP activate
G331I
-
50% of wild-type glutaminase activity, reduced inhibition by GMP, enhanced inhibition by AMP
K326Q/P410W
-
binding of GMP and AMP is abolished resulting in loss of inhibition
L415A
mutant has reduced transfer efficiency. The L415A GPATase mutant-thioester-5'-phosphoribosylpyrophosphate complex after 39 ps, shows the leakage of ammonia into bulk solution
N351A
-
approx. 50% of wild-type glutaminase activity, completely insensitive to inhibition by GMP, partially resistent to inhibition by AMP
P410W
-
reduced inhibition by AMP, strong synergistic inhibition by AMP and GMP
R26H
-
extremely labile enzyme
Y258A
-
complete loss of glutaminase and amidotransferase activity
Y258F
-
approx. 50% loss of glutaminase activity, very weak amidotransferase activity
Y329A
-
normal glutaminase activity, approx. 20% amidotransferase activity, less sensitive to GMP inhibition than wild-type
Y465A
-
100% of wild-type glutaminase activity, 28% of wild-type amidotransferase activity, inhibition by GMP and AMP is similar to wild-type
Y74A
-
complete loss of glutaminase activity, little loss of amidotransferase activity
I198V
by missense mutation A592G, purF(I198V) and variant purF(1-04) in pCA24N by two polymerase error prone PCR strategy (1. mutazyme, 2. Taq DNA polymerase in Thermopol reaction buffer) followed by second directed mutagenesis on purF(1-04) by passaging through Escherichia coli mutator strain XL1-Red leading to variant purF(2-02), mutant I198V and variants 1-04 and 2-02 improved growth of Escherichia coli JMB9 DELTA TrpF (auxotrophic for tryptophan) on medium lacking tryptophan by gained phosphoribosylanthranilate isomerase activity
N328S
recurring mutation after error-prone PCR, found in variant 1-04 of mutant I198V which also harbours mutations: I37M, A39T, E85G, P88S, N124S, I198V, K282R and one silent, Asn328 is implicated in PRPP binding and a critical residue for improving phosphoribosylanthranilate isomerase activity. Variant 2-02 has the same open reading frame as 1-04 but optimized transcription.
additional information
-
enzyme deletion mutant, auxotrophic for adenine, produces lower levels of riboflavin than wild-type
APPLICATION
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
additional information
marginal secondary enzyme activities can dramatically improve the fitness of contemporary organisms
Show AA Sequence (10634 entries)
Longer loading times are possible. Please use the Sequence Search for a certain query.