CHIB_EMEND
ID CHIB_EMEND Reviewed; 398 AA.
AC Q92222; Q5B3K9;
DT 09-JUL-2014, integrated into UniProtKB/Swiss-Prot.
DT 02-AUG-2005, sequence version 3.
DT 03-AUG-2022, entry version 124.
DE RecName: Full=Endochitinase B {ECO:0000303|PubMed:17455791};
DE EC=3.2.1.14 {ECO:0000269|PubMed:17119968, ECO:0000269|PubMed:17455791};
DE AltName: Full=Chitinase B {ECO:0000303|PubMed:17119968};
GN Name=chiB {ECO:0000303|PubMed:17119968, ECO:0000303|PubMed:17455791};
OS Emericella nidulans (Aspergillus nidulans).
OC Eukaryota; Fungi; Dikarya; Ascomycota; Pezizomycotina; Eurotiomycetes;
OC Eurotiomycetidae; Eurotiales; Aspergillaceae; Aspergillus;
OC Aspergillus subgen. Nidulantes.
OX NCBI_TaxID=162425;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA], FUNCTION, CATALYTIC ACTIVITY, DISRUPTION
RP PHENOTYPE, AND INDUCTION.
RC STRAIN=FGSC 89;
RX PubMed=17119968; DOI=10.1007/s00294-006-0109-7;
RA Yamazaki H., Yamazaki D., Takaya N., Takagi M., Ohta A., Horiuchi H.;
RT "A chitinase gene, chiB, involved in the autolytic process of Aspergillus
RT nidulans.";
RL Curr. Genet. 51:89-98(2007).
RN [2]
RP FUNCTION, CATALYTIC ACTIVITY, SUBSTRATE SPECIFICITY, SUBCELLULAR LOCATION,
RP DEVELOPMENTAL STAGE, INDUCTION, AND IDENTIFICATION BY MASS SPECTROMETRY.
RC STRAIN=FGSC 26 {ECO:0000303|PubMed:17455791};
RX PubMed=17455791; DOI=10.1007/bf02931619;
RA Pusztahelyi T., Molnar Z., Emri T., Klement E., Miskei M., Kerekgyarto J.,
RA Balla J., Pocsi I.;
RT "Comparative studies of differential expression of chitinolytic enzymes
RT encoded by chiA, chiB, chiC and nagA genes in Aspergillus nidulans.";
RL Folia Microbiol. (Praha) 51:547-554(2006).
CC -!- FUNCTION: Major secreted chitinase involved in the degradation of
CC chitin, a component of the cell walls of fungi and exoskeletal elements
CC of some animals (including worms and arthropods) (PubMed:17119968,
CC PubMed:17455791). Plays a role in the morphogenesis and autolysis. Has
CC also significant antifungal activity against various fungal species
CC (PubMed:17119968). Hydrolyzes chitin. Hydrolyzes glycol chitosan very
CC effectively and liberates also reducing sugars from cell debris.
CC Hydrolyzes synthetic substrates 4-nitrophenyl N,N'-diacetyl-beta-D-
CC chitobioside (4NP(GlcNAc)2) and 4-nitrophenyl N,N',N''-triacetyl-beta-
CC D-chitotrioside (4NP(GlcNAc)3), but has no activity against 4-
CC nitrophenyl N-acetyl-beta-D-glucosaminide (4NPGlcNAc)
CC (PubMed:17455791). {ECO:0000269|PubMed:17119968,
CC ECO:0000269|PubMed:17455791}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=Random endo-hydrolysis of N-acetyl-beta-D-glucosaminide
CC (1->4)-beta-linkages in chitin and chitodextrins.; EC=3.2.1.14;
CC Evidence={ECO:0000269|PubMed:17119968, ECO:0000269|PubMed:17455791};
CC -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:17455791}.
CC -!- DEVELOPMENTAL STAGE: Highly expressed during the stationary phase and
CC high levels remain in the autolytic stage.
CC {ECO:0000269|PubMed:17455791}.
CC -!- INDUCTION: Expression is increased when the wild-type mycelia are
CC starved for carbon sources, a condition that induces hyphal autolysis
CC (PubMed:17119968). Significantly up-regulated expression with colloidal
CC chitin and chito-oligomers, namely N-acetyl-D-glucosamine (GlcNAc),
CC N,N'-diacetylchitobiose (GlcNAc)2 and N,N',N''-triacetylchitotriose
CC (GlcNAc)3. Expression is not affected by changes in the levels of
CC reactive oxygen species or in the glutathione-glutathione disulfide
CC redox balance, the changes which are physiological characteristics
CC developing in aging and autolyzing fungal cultures. Down-regulated by
CC the oxidative-stress-generating agent diamide, but not by menadione or
CC hydrogen peroxide (PubMed:17455791). {ECO:0000269|PubMed:17119968,
CC ECO:0000269|PubMed:17455791}.
CC -!- DISRUPTION PHENOTYPE: Does not affect germination efficiency nor hyphal
CC growth rate, but considerably reduces the intracellular and
CC extracellular chitinase activities. {ECO:0000269|PubMed:17119968}.
CC -!- SIMILARITY: Belongs to the glycosyl hydrolase 18 family. Chitinase
CC class V subfamily. {ECO:0000305}.
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DR EMBL; D87063; BAA35140.2; -; Genomic_DNA.
DR AlphaFoldDB; Q92222; -.
DR SMR; Q92222; -.
DR CAZy; GH18; Glycoside Hydrolase Family 18.
DR CLAE; CHI18B_EMENI; -.
DR OMA; NPMTYDF; -.
DR GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR GO; GO:0008061; F:chitin binding; IEA:InterPro.
DR GO; GO:0004568; F:chitinase activity; IEA:UniProtKB-EC.
DR GO; GO:0006032; P:chitin catabolic process; IEA:UniProtKB-KW.
DR GO; GO:0000272; P:polysaccharide catabolic process; IEA:UniProtKB-KW.
DR Gene3D; 3.10.50.10; -; 1.
DR InterPro; IPR011583; Chitinase_II.
DR InterPro; IPR029070; Chitinase_insertion_sf.
DR InterPro; IPR001223; Glyco_hydro18_cat.
DR InterPro; IPR001579; Glyco_hydro_18_chit_AS.
DR InterPro; IPR017853; Glycoside_hydrolase_SF.
DR Pfam; PF00704; Glyco_hydro_18; 1.
DR SMART; SM00636; Glyco_18; 1.
DR SUPFAM; SSF51445; SSF51445; 1.
DR SUPFAM; SSF54556; SSF54556; 1.
DR PROSITE; PS01095; GH18_1; 1.
DR PROSITE; PS51910; GH18_2; 1.
PE 1: Evidence at protein level;
KW Carbohydrate metabolism; Chitin degradation; Glycoprotein; Glycosidase;
KW Hydrolase; Polysaccharide degradation; Secreted.
FT CHAIN 1..398
FT /note="Endochitinase B"
FT /id="PRO_0000429826"
FT DOMAIN 4..363
FT /note="GH18"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01258"
FT ACT_SITE 138
FT /note="Proton donor"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01258"
FT BINDING 69..70
FT /ligand="chitin"
FT /ligand_id="ChEBI:CHEBI:17029"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01258"
FT BINDING 96..99
FT /ligand="chitin"
FT /ligand_id="ChEBI:CHEBI:17029"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01258"
FT BINDING 139
FT /ligand="chitin"
FT /ligand_id="ChEBI:CHEBI:17029"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01258"
FT BINDING 200..203
FT /ligand="chitin"
FT /ligand_id="ChEBI:CHEBI:17029"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01258"
FT BINDING 342
FT /ligand="chitin"
FT /ligand_id="ChEBI:CHEBI:17029"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01258"
FT CARBOHYD 66
FT /note="N-linked (GlcNAc...) asparagine"
FT /evidence="ECO:0000255"
FT CARBOHYD 103
FT /note="N-linked (GlcNAc...) asparagine"
FT /evidence="ECO:0000255"
SQ SEQUENCE 398 AA; 44206 MW; 216EC8D89DD48B1B CRC64;
MSGYKTVGYF VNWAIYGRNY NPQDLPAEKL THILYAFANV RPETGEVYLS DTWSDIEKHY
PTDSWNDTGN NVYGCVKQLG LLKRQHRQLK VLLSIGGWTY SPNFTNGAGT PENRARFAQT
ATKLITDLGF DGIDIDWEYP QNDQQAQNYV DLLRRCREAL NAAQGQRRFQ LTVAVPAGPD
NYNKLRLQEM TPYLDFYNLM AYDYAGSWDQ TAGHQANLYP STSNPTSTPF NTVQAVNHYI
DAGGVPSNKI ILGMPIYGRA FQNTDGPGRP YSGIGQGTWE QGVYDYKALP RPGATEQLDT
NIGASWSYDP SSREMVSYDT VAAADLKAAY IQSRRLGGAM WWETSADKGG KTANKADGSL
IGTFVEDVGG VNNLDRTQNA ISYPDSQYDN LKAGFPSS
