Information on EC 3.2.1.200 - exo-chitinase (non-reducing end)

Please wait a moment until all data is loaded. This message will disappear when all data is loaded.
Specify your search results
Select one or more organisms in this record:


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

EC NUMBER
COMMENTARY hide
3.2.1.200
-
RECOMMENDED NAME
GeneOntology No.
exo-chitinase (non-reducing end)
-
REACTION
REACTION DIAGRAM
COMMENTARY hide
ORGANISM
UNIPROT
LITERATURE
Hydrolysis of N,N'-diacetylchitobiose from the non-reducing end of chitin and chitodextrins
show the reaction diagram
-
-
-
-
PATHWAY
BRENDA Link
KEGG Link
MetaCyc Link
chitin degradation I (archaea)
-
-
chitin degradation III (Serratia)
-
-
SYSTEMATIC NAME
IUBMB Comments
(1->4)-2-acetamido-2-deoxy-beta-D-glucan diacetylchitobiohydrolase (non-reducing end)
The enzyme hydrolyses the second glycosidic (1->4) linkage from non-reducing ends of chitin and chitodextrin molecules, liberating N,N'-diacetylchitobiose disaccharides. cf. EC 3.2.1.201, exo-chitinase (reducing end).
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
4'-methylumbelliferyl-N,N',N''-triacetylchitobiose + H2O
methylumbelliferone + N,N',N''-triacetylchitobiose
show the reaction diagram
4'-methylumbelliferyl-N,N'-diacetylchitobiose + H2O
methylumbelliferone + N,N'-diacetylchitobiose
show the reaction diagram
beta-chitin + H2O
?
show the reaction diagram
chitosan + H2O
?
show the reaction diagram
-
65% acetylated chitosan, enzyme shows a processive mode of action, moving the sugar chain two residues at a time and almost exclusively yielding oligomers with even-numbered chain lengths
-
?
colloidal chitin + H2O
N,N'-diacetylchitobiose + ?
show the reaction diagram
-
the enzyme processively cleaves off chitobiose from the nonreducing end of chitin or other chitooligomers
-
-
?
colloidal chitin + H2O
N-acetylglucosamine + N,N#-diacetylchitobiose + ?
show the reaction diagram
crab shell chitin + H2O
N,N'-diacetylchitobiose + ?
show the reaction diagram
-
the enzyme processively cleaves off chitobiose from the nonreducing end of chitin or other chitooligomers
-
-
?
GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAc + H2O
2 N,N'-diacetylchitobiose
show the reaction diagram
-
the enzyme processively cleaves off chitobiose from the nonreducing end of chitin or other chitooligomers
-
-
?
GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAc + H2O
N,N'-diacetylchitobiose + ?
show the reaction diagram
-
the enzyme processively cleaves off chitobiose from the nonreducing end of chitin or other chitooligomers
-
-
?
GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAc + H2O
N,N'-diacetylchitobiose + GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAcbeta
show the reaction diagram
-
ChiBcat hydrolyzes chitooligosaccharides (degree of polymerization = 3 to 6), yielding predominantly chitobiose. (GlcNAc)6 is processively degraded to mostly (GlcNAc)4 and (GlcNAc)2, with limited formation of (GlcNAc)3
-
-
?
N,N',N'',N''',N'''',N'''''-hexaacetylchitohexaose + H2O
N,N'-diacetylchitobiose + N,N',N'',N'''-tetraacetylchitotetraose
show the reaction diagram
N,N',N'',N''',N''''-pentaacetylchitopentaose + H2O
N,N'-diacetylchitobiose + N,N',N''-triacetylchitotriose
show the reaction diagram
-
-
-
?
N,N',N'',N'''-tetraacetylchitotetraose + H2O
2 N,N'-diacetylchitobiose
show the reaction diagram
additional information
?
-
METALS and IONS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
KCl
0.2-1 mM, 110% of initial activity
NaCl
0.2-1 mM, 110% of initial activity
INHIBITORS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
Cu2+
10 mM, 41% loss of activity
GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAc
-
substrate inhibition
GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAc
-
substrate inhibition
GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAc
-
substrate inhibition
Hg2+
10 mM, complete loss of activity
Ni2+
10 mM, 36% loss of activity
additional information
not inhibitory or activating: Mg2+, Mn2+, Ca2+, K+, EDTA, EGTA, or 1.0 M NaCl
-
ACTIVATING COMPOUND
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
additional information
not inhibitory or activating: Mg2+, Mn2+, Ca2+, K+, EDTA, EGTA, or 1.0 M NaCl
-
KM VALUE [mM]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
0.13
GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAc
-
pH 6, 95C
0.3
GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAc
-
pH 6, 95C
0.24
GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAc
-
pH 6, 95C
kcat/KM VALUE [1/mMs-1]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
13380
GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAc
-
pH 6, 95C
13490
GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAc
-
pH 6, 95C
8580
GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAc
-
pH 6, 95C
Ki VALUE [mM]
INHIBITOR
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
5.89
GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAc
-
pH 6, 95C
2.56
GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAc
-
pH 6, 95C
2.15
GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAcbeta(1->4)GlcNAc
-
pH 6, 95C
SPECIFIC ACTIVITY [µmol/min/mg]
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
5900
substrate 4'-methylumbelliferyl-N,N',N''-triacetylchitobiose, aminoterminal catalytic domain, pH 7.5, 30C
80000
substrate 4'-methylumbelliferyl-N,N'-diacetylchitobiose, aminoterminal catalytic domain, pH 7.5, 30C
pH OPTIMUM
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
TEMPERATURE OPTIMUM
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
95
-
assay at
TEMPERATURE RANGE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
30
80% of maximum activity
SUBUNITS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
POSTTRANSLATIONAL MODIFICATION
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
proteolytic modification
protein contains a signal sequence consisting of 24 amino acid residues at the N-terminus
Crystallization/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
to 2.0 A resolution, and docking simulation with substrate N,N',N'',N''',N''''-pentaacetylchitopentaose
ChiB comprises a catalytic (beta/alpha)8 barrel domain and a C-terminal putative chitin-binding domain. The cocrystallized chito-oligosaccharide is inserted into the catalytic cleft from the non-reducing end when digested by ChiB
pH STABILITY
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
TEMPERATURE STABILITY
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
80
stable for 60 min
114
-
melting temperature
Purification/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
Cloned/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
expression in Escherichia coli
the chiB gene sequence transcription and translation in Escherichia coli may be blocked by a RNA folding mechanism
EXPRESSION
ORGANISM
UNIPROT
LITERATURE
expression is induced by both biotic and abiotic stress
APPLICATION
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
agriculture