ID   CHIB_MAIZE              Reviewed;         269 AA.
AC   P29023;
DT   01-DEC-1992, integrated into UniProtKB/Swiss-Prot.
DT   01-DEC-1992, sequence version 1.
DT   03-AUG-2022, entry version 126.
DE   RecName: Full=Endochitinase B;
DE            EC=3.2.1.14;
DE   AltName: Full=Seed chitinase B;
DE   Flags: Precursor; Fragment;
OS   Zea mays (Maize).
OC   Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC   Spermatophyta; Magnoliopsida; Liliopsida; Poales; Poaceae; PACMAD clade;
OC   Panicoideae; Andropogonodae; Andropogoneae; Tripsacinae; Zea.
OX   NCBI_TaxID=4577;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC   TISSUE=Seed;
RX   PubMed=1551872; DOI=10.1016/s0021-9258(19)50474-4;
RA   Huynh Q.K., Hironaka C.M., Levine E.B., Smith C.E., Borgmeyer J.R.,
RA   Shah D.M.;
RT   "Antifungal proteins from plants. Purification, molecular cloning, and
RT   antifungal properties of chitinases from maize seed.";
RL   J. Biol. Chem. 267:6635-6640(1992).
RN   [2]
RP   PROTEIN SEQUENCE OF 169-184.
RC   TISSUE=Seed;
RX   PubMed=1740436; DOI=10.1016/s0021-9258(19)50609-3;
RA   Verburg J.G., Smith C.E., Lisek C.A., Huynh Q.K.;
RT   "Identification of an essential tyrosine residue in the catalytic site of a
RT   chitinase isolated from Zea mays that is selectively modified during
RT   inactivation with 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide.";
RL   J. Biol. Chem. 267:3886-3893(1992).
CC   -!- FUNCTION: Defense against chitin-containing fungal pathogens.
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   -!- MISCELLANEOUS: Maize chitinase B seems to be less active than chitinase
CC       A.
CC   -!- SIMILARITY: Belongs to the glycosyl hydrolase 19 family. Chitinase
CC       class I subfamily. {ECO:0000305}.
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DR   EMBL; M84165; AAA33445.1; -; Genomic_DNA.
DR   PIR; B42424; B42424.
DR   AlphaFoldDB; P29023; -.
DR   SMR; P29023; -.
DR   STRING; 4577.GRMZM2G005633_P02; -.
DR   Allergome; 7663; Zea m 8.
DR   CAZy; CBM18; Carbohydrate-Binding Module Family 18.
DR   CAZy; GH19; Glycoside Hydrolase Family 19.
DR   PaxDb; P29023; -.
DR   PRIDE; P29023; -.
DR   MaizeGDB; 25130; -.
DR   eggNOG; KOG4742; Eukaryota.
DR   Proteomes; UP000007305; Unplaced.
DR   ExpressionAtlas; P29023; baseline and differential.
DR   GO; GO:0008061; F:chitin binding; IEA:UniProtKB-KW.
DR   GO; GO:0004568; F:chitinase activity; IBA:GO_Central.
DR   GO; GO:0016998; P:cell wall macromolecule catabolic process; IEA:InterPro.
DR   GO; GO:0006032; P:chitin catabolic process; IEA:UniProtKB-KW.
DR   GO; GO:0006952; P:defense response; IEA:UniProtKB-KW.
DR   GO; GO:0000272; P:polysaccharide catabolic process; IEA:UniProtKB-KW.
DR   Gene3D; 3.30.60.10; -; 1.
DR   InterPro; IPR001002; Chitin-bd_1.
DR   InterPro; IPR018371; Chitin-binding_1_CS.
DR   InterPro; IPR036861; Endochitinase-like_sf.
DR   InterPro; IPR016283; Glyco_hydro_19.
DR   InterPro; IPR000726; Glyco_hydro_19_cat.
DR   InterPro; IPR023346; Lysozyme-like_dom_sf.
DR   Pfam; PF00187; Chitin_bind_1; 1.
DR   Pfam; PF00182; Glyco_hydro_19; 2.
DR   PIRSF; PIRSF001060; Endochitinase; 1.
DR   PRINTS; PR00451; CHITINBINDNG.
DR   SMART; SM00270; ChtBD1; 1.
DR   SUPFAM; SSF53955; SSF53955; 1.
DR   SUPFAM; SSF57016; SSF57016; 1.
DR   PROSITE; PS00026; CHIT_BIND_I_1; 1.
DR   PROSITE; PS50941; CHIT_BIND_I_2; 1.
DR   PROSITE; PS00773; CHITINASE_19_1; 1.
DR   PROSITE; PS00774; CHITINASE_19_2; 1.
PE   1: Evidence at protein level;
KW   Carbohydrate metabolism; Chitin degradation; Chitin-binding;
KW   Direct protein sequencing; Disulfide bond; Glycosidase; Hydrolase;
KW   Plant defense; Polysaccharide degradation; Reference proteome; Signal.
FT   SIGNAL          <1..20
FT                   /evidence="ECO:0000255"
FT   CHAIN           21..269
FT                   /note="Endochitinase B"
FT                   /id="PRO_0000005304"
FT   DOMAIN          21..55
FT                   /note="Chitin-binding type-1"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00261"
FT   REGION          58..66
FT                   /note="Hinge region (Gly-rich)"
FT   REGION          67..269
FT                   /note="Catalytic"
FT   ACT_SITE        133
FT                   /note="Proton donor"
FT                   /evidence="ECO:0000250|UniProtKB:P29022"
FT   DISULFID        23..31
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00261"
FT   DISULFID        25..37
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00261"
FT   DISULFID        30..44
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00261"
FT   DISULFID        48..53
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00261"
FT   DISULFID        89..138
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00261"
FT   DISULFID        150..159
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00261"
FT   DISULFID        237..269
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00261"
FT   NON_TER         1
SQ   SEQUENCE   269 AA;  28166 MW;  3D38B1BADF75DE8F CRC64;
     PQLVALGLAL LCAVAGPAAA QNCGCQPNVC CSKFGYCGTT DEYCGDGCQS GPCRSGRGGG
     GSGGGGANVA SVVTSSFFNG IKNQAGSGCE GKNFYTRSAF LSAVKGYPGF AHGGSQVQGK
     REIAAFFAHA THETGHFCYI SEINKSNAYC DPTKRQWPCA AGQKYYGRGP LQISWNYNYG
     PAGRAIGFDG LGDPGRVARD AVVAFKAALW FWMNSVHGVV PQGFGATTRA MQRALECGGN
     NPAQMNARVG YYRQYCRQLG VDPGPNLTC