3.2.1.200: exo-chitinase (non-reducing end)
This is an abbreviated version!
For detailed information about exo-chitinase (non-reducing end), go to the full flat file.
Reaction
Hydrolysis of N,N'-diacetylchitobiose from the non-reducing end of chitin and chitodextrins =
Synonyms
At4g19810, ChiA, ChiA 65, ChiB, ChiC, chitinase B, GH18 chitinase, TdsC, Tfu0868
ECTree
3.2.1.200 exo-chitinase (non-reducing end)Advanced search results
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Substrates Products on EC 3.2.1.200 - exo-chitinase (non-reducing end)
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SUBSTRATE 
PRODUCT
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate)
(Substrate)
LITERATURE
(Substrate)
(Substrate)
COMMENTARY
(Product)
(Product)
LITERATURE
(Product)
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
r=reversible
ir=irreversible
?=not specified
4-methylumbelliferyl beta-D-N,N'-diacetylchitobioside + H2O
4-methylumbelliferone + beta-D-N,N'-diacetylchitobiose
-
-
-
?
4-methylumbelliferyl beta-N,N',N''-triacetylchitotrioside + H2O
methylumbelliferone + N,N',N''-triacetylchitotriose
4-methylumbelliferyl N,N'-diacetylchitobioside + H2O
methylumbelliferone + N,N'-diacetylchitobiose
4-nitrophenyl beta-N,N',N'', N'''-tetraacetylchitotetraoside + H2O
?
-
-
-
?
4-nitrophenyl beta-N,N',N''-triacetylchitotrioside + H2O
?
-
-
-
?
4-nitrophenyl beta-N,N'-diacetylchitobioside + H2O
?
-
-
-
?
chitosan + H2O
?
-
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
-
?
crab shell chitin + H2O
N,N'-diacetylchitobiose + ?
-
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
-
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 + ?
-
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
-
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',N''-triacetylchitotriose + N,N'-diacetylchitobiose + N,N',N'',N'''-tetraacetylchitotetraose
-
-
-
?
N,N',N'',N''',N'''',N'''''-hexaacetylchitohexaose + H2O
N,N'-diacetylchitobiose + N,N',N'',N'''-tetraacetylchitotetraose
N,N',N'',N''',N''''-pentaacetylchitopentaose + H2O
N,N'-diacetylchitobiose + N,N',N''-triacetylchitotriose
4-methylumbelliferyl beta-D-N,N'-diacetylchitobioside + H2O
?
-
-
-
?
4-methylumbelliferyl beta-D-N,N'-diacetylchitobioside + H2O
?
-
-
-
?
4-methylumbelliferyl beta-N,N',N''-triacetylchitotrioside + H2O
methylumbelliferone + N,N',N''-triacetylchitotriose
-
-
-
?
4-methylumbelliferyl beta-N,N',N''-triacetylchitotrioside + H2O
methylumbelliferone + N,N',N''-triacetylchitotriose
-
-
-
?
4-methylumbelliferyl N,N'-diacetylchitobioside + H2O
methylumbelliferone + N,N'-diacetylchitobiose
-
-
-
?
4-methylumbelliferyl N,N'-diacetylchitobioside + H2O
methylumbelliferone + N,N'-diacetylchitobiose
-
-
-
?
beta-chitin + H2O
?
-
ChiB is active from the nonreducing end to the reducing end
-
?
beta-chitin + H2O
?
-
ChiB is active from the nonreducing end to the reducing end
-
?
colloidal chitin + H2O
N,N'-diacetylchitobiose + ?
-
the enzyme processively cleaves off chitobiose from the nonreducing end of chitin or other chitooligomers
-
-
?
colloidal chitin + H2O
N-acetyl beta-D-glucosamine + chitobiose + chitotriose
-
-
-
-
?
colloidal chitin + H2O
N-acetyl beta-D-glucosamine + chitobiose + chitotriose
Trichocladium griseum ITCC 10,360.16
-
-
-
-
?
colloidal chitin + H2O
N-acetylglucosamine + N,N'-diacetylchitobiose + ?
-
ChiB produces relatively large amounts of chitin monomer and dimer, but very low amounts of trimer
-
?
colloidal chitin + H2O
N-acetylglucosamine + N,N'-diacetylchitobiose + ?
-
ChiB produces relatively large amounts of chitin monomer and dimer, but very low amounts of trimer
-
?
crystalline beta-chitin + H2O
N,N'-diacetylchitobiose + ?
the enzyme degrades the chitin from the non-reducing end
-
-
?
crystalline beta-chitin + H2O
N,N'-diacetylchitobiose + ?
the enzyme degrades the chitin from the non-reducing end
-
-
?
high molecular weight chitin + H2O
?
-
90% activity compared to colloidal chitin
-
-
?
high molecular weight chitin + H2O
?
Aspergillus griseoaurantiacus KX010988
-
90% activity compared to colloidal chitin
-
-
?
moderate molecular weight chitin + H2O
?
-
40% activity compared to colloidal chitin
-
-
?
moderate molecular weight chitin + H2O
?
Aspergillus griseoaurantiacus KX010988
-
40% activity compared to colloidal chitin
-
-
?
N,N',N'',N''',N'''',N'''''-hexaacetylchitohexaose + H2O
N,N'-diacetylchitobiose + N,N',N'',N'''-tetraacetylchitotetraose
-
-
-
?
N,N',N'',N''',N'''',N'''''-hexaacetylchitohexaose + H2O
N,N'-diacetylchitobiose + N,N',N'',N'''-tetraacetylchitotetraose
-
-
-
?
N,N',N'',N''',N'''',N'''''-hexaacetylchitohexaose + H2O
N,N'-diacetylchitobiose + N,N',N'',N'''-tetraacetylchitotetraose
-
-
-
?
N,N',N'',N''',N''''-pentaacetylchitopentaose + H2O
N,N'-diacetylchitobiose + N,N',N''-triacetylchitotriose
-
-
-
?
N,N',N'',N''',N''''-pentaacetylchitopentaose + H2O
N,N'-diacetylchitobiose + N,N',N''-triacetylchitotriose
-
-
-
?
N,N',N'',N'''-tetraacetylchitotetraose + H2O
2 N,N'-diacetylchitobiose
-
-
-
?
N,N',N'',N'''-tetraacetylchitotetraose + H2O
2 N,N'-diacetylchitobiose
-
sole product
-
?
N,N',N'',N'''-tetraacetylchitotetraose + H2O
2 N,N'-diacetylchitobiose
-
sole product
-
?
N,N',N'',N'''-tetraacetylchitotetraose + H2O
2 N,N'-diacetylchitobiose
-
-
-
?
additional information
?
-
the enzyme hydrolyzes N-acetylglucosamine oligomers producing dimers from the nonreducing end of the substrates. It shows predominantly exo-splitting mode, but contains a slight endo-splitting activity and catalyzes an anomeric retention reaction. The enzyme catalyzes transglycosylation reaction in a low efficiency
-
-
?
additional information
?
-
-
no activity with low molecular weight chitin. The enzyme is not active on rice bran, rice straw, corn stalks, corn leaves and bagasse
-
-
?
additional information
?
-
Aspergillus griseoaurantiacus KX010988
-
no activity with low molecular weight chitin. The enzyme is not active on rice bran, rice straw, corn stalks, corn leaves and bagasse
-
-
?
additional information
?
-
the enzmye preferentially hydrolyzes the second glycosidic link from the non-reducing end of (GlcNAc)n
-
-
?
additional information
?
-
-
no activity with chitobiose and 4-nitrophenyl-N-acetylglucosamine
-
-
?
additional information
?
-
ChiB is an exoenzyme which degrades the polymer chains from their nonreducing ends. The degradation of chitosan with 65% acetylated units showed biphasic kinetics: the faster phase is dominated by cleavage on the reducing side of two acetylated units (occupying subsites -2 and -1), while the slower kinetic phase reflects cleavage on the reducing side of a deacetylated and an acetylated unit (bound to subsites -2 and -1, respectively). The enzyme does not show preferences with respect to acetylation of the sugar bound in the +1 subsite. Even chitosans with low degrees of acetylation can be degraded by ChiB
-
-
?
additional information
?
-
-
processive enzyme, in which the substrate remains bound to the active cleft after successful hydrolysis and is moved along for the next hydrolysis to occur. ChiB performs on average 3.4 cleavages, for the formation of each enzyme-substrate complex. The exo-type of activity observed for ChiB during the degradation of solid crystalline chitin is due to the better accessibility of chain ends. When hydrolyzing soluble substrates, ChiB operates in a processive endo-attack mode of action
-
-
?
additional information
?
-
no activity with N,N',N''-triacetylchitotriose
-
-
?
