ID   CHIS_NIACI              Reviewed;         301 AA.
AC   P33673;
DT   01-FEB-1994, integrated into UniProtKB/Swiss-Prot.
DT   01-MAR-2004, sequence version 2.
DT   03-AUG-2022, entry version 104.
DE   RecName: Full=Chitosanase;
DE            EC=3.2.1.132;
DE   Flags: Precursor;
GN   Name=csn;
OS   Niallia circulans (Bacillus circulans).
OC   Bacteria; Firmicutes; Bacilli; Bacillales; Bacillaceae; Niallia.
OX   NCBI_TaxID=1397;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA], AND PARTIAL PROTEIN SEQUENCE.
RC   STRAIN=MH-K1;
RA   Ando A., Noguchi K., Yanagi M., Shinoyama H., Kagawa Y., Hirata H.,
RA   Yabuki M., Fujii T.;
RT   "Primary structure of chitosanase produced by Bacillus circulans MH-K1.";
RL   J. Gen. Appl. Microbiol. 38:135-144(1992).
RN   [2]
RP   SEQUENCE REVISION TO 119-124; 140 AND 200-202.
RA   Ando A.;
RL   Submitted (OCT-2002) to the EMBL/GenBank/DDBJ databases.
RN   [3]
RP   X-RAY CRYSTALLOGRAPHY (1.6 ANGSTROMS) OF 43-301.
RC   STRAIN=MH-K1;
RX   PubMed=10521473; DOI=10.1074/jbc.274.43.30818;
RA   Saito J., Kita A., Higuchi Y., Nagata Y., Ando A., Miki K.;
RT   "Crystal structure of chitosanase from Bacillus circulans MH-K1 at 1.6-A
RT   resolution and its substrate recognition mechanism.";
RL   J. Biol. Chem. 274:30818-30825(1999).
CC   -!- FUNCTION: Aids in the defense against invading fungal pathogens by
CC       degrading their cell wall chitosan.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=Endohydrolysis of beta-(1->4)-linkages between D-glucosamine
CC         residues in a partly acetylated chitosan.; EC=3.2.1.132;
CC   -!- SUBCELLULAR LOCATION: Secreted.
CC   -!- SIMILARITY: Belongs to the glycosyl hydrolase 46 family. {ECO:0000305}.
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DR   EMBL; D10624; BAA01474.2; -; Genomic_DNA.
DR   PDB; 1QGI; X-ray; 1.60 A; A=43-301.
DR   PDB; 2D05; X-ray; 2.00 A; A=43-301.
DR   PDB; 5HWA; X-ray; 1.35 A; A=43-301.
DR   PDBsum; 1QGI; -.
DR   PDBsum; 2D05; -.
DR   PDBsum; 5HWA; -.
DR   AlphaFoldDB; P33673; -.
DR   SMR; P33673; -.
DR   CAZy; GH46; Glycoside Hydrolase Family 46.
DR   KEGG; ag:BAA01474; -.
DR   BioCyc; MetaCyc:MON-17652; -.
DR   BRENDA; 3.2.1.132; 649.
DR   EvolutionaryTrace; P33673; -.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0016977; F:chitosanase activity; IEA:UniProtKB-EC.
DR   GO; GO:0005975; P:carbohydrate metabolic process; IEA:InterPro.
DR   CDD; cd00978; chitosanase_GH46; 1.
DR   Gene3D; 3.30.386.10; -; 1.
DR   InterPro; IPR000400; Glyco_hydro_46.
DR   InterPro; IPR023099; Glyco_hydro_46_N.
DR   InterPro; IPR023346; Lysozyme-like_dom_sf.
DR   Pfam; PF01374; Glyco_hydro_46; 1.
DR   PIRSF; PIRSF036551; Chitosanase; 1.
DR   SUPFAM; SSF53955; SSF53955; 1.
DR   PROSITE; PS60000; CHITOSANASE_46_80; 1.
PE   1: Evidence at protein level;
KW   3D-structure; Direct protein sequencing; Disulfide bond; Glycosidase;
KW   Hydrolase; Secreted; Signal.
FT   SIGNAL          1..42
FT   CHAIN           43..301
FT                   /note="Chitosanase"
FT                   /id="PRO_0000012206"
FT   ACT_SITE        79
FT                   /note="Proton donor"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU10070"
FT   ACT_SITE        97
FT                   /note="Nucleophile"
FT                   /evidence="ECO:0000250"
FT   DISULFID        92..166
FT   HELIX           45..48
FT                   /evidence="ECO:0007829|PDB:5HWA"
FT   HELIX           51..61
FT                   /evidence="ECO:0007829|PDB:5HWA"
FT   HELIX           65..80
FT                   /evidence="ECO:0007829|PDB:5HWA"
FT   STRAND          81..83
FT                   /evidence="ECO:0007829|PDB:5HWA"
FT   HELIX           85..88
FT                   /evidence="ECO:0007829|PDB:5HWA"
FT   STRAND          96..99
FT                   /evidence="ECO:0007829|PDB:5HWA"
FT   TURN            104..107
FT                   /evidence="ECO:0007829|PDB:5HWA"
FT   STRAND          115..117
FT                   /evidence="ECO:0007829|PDB:5HWA"
FT   HELIX           120..130
FT                   /evidence="ECO:0007829|PDB:5HWA"
FT   HELIX           138..144
FT                   /evidence="ECO:0007829|PDB:5HWA"
FT   STRAND          149..152
FT                   /evidence="ECO:0007829|PDB:5HWA"
FT   STRAND          155..158
FT                   /evidence="ECO:0007829|PDB:5HWA"
FT   HELIX           162..170
FT                   /evidence="ECO:0007829|PDB:5HWA"
FT   TURN            171..174
FT                   /evidence="ECO:0007829|PDB:5HWA"
FT   HELIX           176..189
FT                   /evidence="ECO:0007829|PDB:5HWA"
FT   HELIX           191..200
FT                   /evidence="ECO:0007829|PDB:5HWA"
FT   HELIX           206..219
FT                   /evidence="ECO:0007829|PDB:5HWA"
FT   STRAND          221..224
FT                   /evidence="ECO:0007829|PDB:5HWA"
FT   HELIX           228..234
FT                   /evidence="ECO:0007829|PDB:5HWA"
FT   HELIX           241..253
FT                   /evidence="ECO:0007829|PDB:5HWA"
FT   TURN            254..257
FT                   /evidence="ECO:0007829|PDB:5HWA"
FT   TURN            259..261
FT                   /evidence="ECO:0007829|PDB:1QGI"
FT   HELIX           266..280
FT                   /evidence="ECO:0007829|PDB:5HWA"
FT   HELIX           289..295
FT                   /evidence="ECO:0007829|PDB:5HWA"
SQ   SEQUENCE   301 AA;  33426 MW;  5B67FB8FF1D1F763 CRC64;
     MHMSNARPSK SRTKFLLAFL CFTLMASLFG ATALFGPSKA AAASPDDNFS PETLQFLRNN
     TGLDGEQWNN IMKLINKPEQ DDLNWIKYYG YCEDIEDERG YTIGLFGATT GGSRDTHPDG
     PDLFKAYDAA KGASNPSADG ALKRLGINGK MKGSILEIKD SEKVFCGKIK KLQNDAAWRK
     AMWETFYNVY IRYSVEQARQ RGFTSAVTIG SFVDTALNQG ATGGSDTLQG LLARSGSSSN
     EKTFMKNFHA KRTLVVDTNK YNKPPNGKNR VKQWDTLVDM GKMNLKNVDS EIAQVTDWEM
     K