ID CHIA1_NIACI Reviewed; 699 AA. AC P20533; DT 01-FEB-1991, integrated into UniProtKB/Swiss-Prot. DT 01-FEB-1991, sequence version 1. DT 04-NOV-2026, entry version 146. DE RecName: Full=Chitinase A1; DE EC=3.2.1.14; DE Flags: Precursor; GN Name=chiA1; OS Niallia circulans (Bacillus circulans). OC Bacteria; Bacillati; Bacillota; Bacilli; Caryophanales; Bacillaceae; OC Niallia. OX NCBI_TaxID=1397; RN [1] RP NUCLEOTIDE SEQUENCE [GENOMIC DNA]. RC STRAIN=WL-12; RX PubMed=2203782; DOI=10.1016/s0021-9258(18)55449-1; RA Watanabe T., Suzuki K., Oyanagi W., Ohnishi K., Tanaka H.; RT "Gene cloning of chitinase A1 from Bacillus circulans WL-12 revealed its RT evolutionary relationship to Serratia chitinase and to the type III RT homology units of fibronectin."; RL J. Biol. Chem. 265:15659-15665(1990). RN [2] RP MUTAGENESIS. RC STRAIN=WL-12; RX PubMed=8103047; DOI=10.1016/s0021-9258(17)46665-8; RA Watanabe T., Kohori K., Miyashita K., Fujii T., Sakai H., Uchida M., RA Tanaka H.; RT "Identification of glutamic acid 204 and aspartic acid 200 in chitinase A1 RT of Bacillus circulans WL-12 as essential residues for chitinase activity."; RL J. Biol. Chem. 268:18567-18572(1993). 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 -!- SIMILARITY: Belongs to the glycosyl hydrolase 18 family. Chitinase CC class II subfamily. {ECO:0000305}. CC --------------------------------------------------------------------------- CC Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms CC Distributed under the Creative Commons Attribution (CC BY 4.0) License CC --------------------------------------------------------------------------- DR EMBL; M57601; AAA81528.1; -; Genomic_DNA. DR PIR; A38368; A38368. DR PDB; 1ED7; NMR; -; A=655-699. DR PDB; 1ITX; X-ray; 1.10 A; A=33-451. DR PDB; 1K85; NMR; -; A=559-644. DR AlphaFoldDB; P20533; -. DR BMRB; P20533; -. DR MDposit; P20533; -. DR SMR; P20533; -. DR CAZy; CBM12; Carbohydrate-Binding Module Family 12. DR CAZy; GH18; Glycoside Hydrolase Family 18. DR BRENDA; 3.2.1.14; 649. DR EvolutionaryTrace; P20533; -. DR GO; GO:0005576; C:extracellular region; IEA:InterPro. DR GO; GO:0030246; F:carbohydrate binding; IEA:InterPro. DR GO; GO:0008061; F:chitin binding; IEA:InterPro. DR GO; GO:0008843; F:endochitinase activity; IEA:UniProtKB-EC. DR GO; GO:0005975; P:carbohydrate metabolic process; IEA:InterPro. DR CDD; cd12214; ChiA1_BD; 1. DR CDD; cd00063; FN3; 2. DR CDD; cd06548; GH18_chitinase; 1. DR FunFam; 2.60.40.10:FF:001114; Chitinase A1; 1. DR FunFam; 3.20.20.80:FF:000153; Chitinase A1; 1. DR Gene3D; 3.10.50.10; -; 1. DR Gene3D; 2.10.10.20; Carbohydrate-binding module superfamily 5/12; 1. DR Gene3D; 3.20.20.80; Glycosidases; 1. DR Gene3D; 2.60.40.10; Immunoglobulins; 2. DR InterPro; IPR003610; CBM5/12. DR InterPro; IPR036573; CBM_sf_5/12. DR InterPro; IPR011583; Chitinase_II/V-like_cat. DR InterPro; IPR029070; Chitinase_insertion_sf. DR InterPro; IPR003961; FN3_dom. DR InterPro; IPR036116; FN3_sf. DR InterPro; IPR017853; GH_hydrolase_sf. DR InterPro; IPR001223; Glyco_hydro18_cat. DR InterPro; IPR001579; Glyco_hydro_18_chit_AS. DR InterPro; IPR050314; Glycosyl_Hydrlase_18. DR InterPro; IPR013783; Ig-like_fold. DR PANTHER; PTHR11177; CHITINASE; 1. DR PANTHER; PTHR11177:SF317; CHITINASE 12-RELATED; 1. DR Pfam; PF02839; CBM_5_12; 1. DR Pfam; PF00041; fn3; 2. DR Pfam; PF00704; Glyco_hydro_18; 1. DR SMART; SM00495; ChtBD3; 1. DR SMART; SM00060; FN3; 2. DR SMART; SM00636; Glyco_18; 1. DR SUPFAM; SSF51445; (Trans)glycosidases; 1. DR SUPFAM; SSF51055; Carbohydrate binding domain; 1. DR SUPFAM; SSF54556; Chitinase insertion domain; 1. DR SUPFAM; SSF49265; Fibronectin type III; 1. DR PROSITE; PS50853; FN3; 2. DR PROSITE; PS01095; GH18_1; 1. DR PROSITE; PS51910; GH18_2; 1. PE 1: Evidence at protein level; KW 3D-structure; Carbohydrate metabolism; Chitin degradation; Glycosidase; KW Hydrolase; Polysaccharide degradation; Repeat; Signal. FT SIGNAL 1..41 FT CHAIN 42..699 FT /note="Chitinase A1" FT /id="PRO_0000011905" FT DOMAIN 44..454 FT /note="GH18" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01258" FT DOMAIN 467..553 FT /note="Fibronectin type-III 1" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00316" FT DOMAIN 562..647 FT /note="Fibronectin type-III 2" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00316" FT REGION 449..471 FT /note="Disordered" FT /evidence="ECO:0000256|SAM:MobiDB-lite" FT COMPBIAS 452..465 FT /note="Low complexity" FT /evidence="ECO:0000256|SAM:MobiDB-lite" FT ACT_SITE 204 FT /note="Proton donor" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01258" FT BINDING 135..136 FT /ligand="chitin" FT /ligand_id="ChEBI:CHEBI:17029" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01258" FT BINDING 162..165 FT /ligand="chitin" FT /ligand_id="ChEBI:CHEBI:17029" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01258" FT BINDING 205 FT /ligand="chitin" FT /ligand_id="ChEBI:CHEBI:17029" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01258" FT BINDING 277..280 FT /ligand="chitin" FT /ligand_id="ChEBI:CHEBI:17029" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01258" FT BINDING 433 FT /ligand="chitin" FT /ligand_id="ChEBI:CHEBI:17029" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01258" FT MUTAGEN 200 FT /note="D->E: No change in activity." FT /evidence="ECO:0000269|PubMed:8103047" FT MUTAGEN 200 FT /note="D->N: Decrease in activity." FT /evidence="ECO:0000269|PubMed:8103047" FT MUTAGEN 204 FT /note="E->D,Q: Loss of activity." FT /evidence="ECO:0000269|PubMed:8103047" FT HELIX 34..38 FT /evidence="ECO:0007829|PDB:1ITX" FT HELIX 40..43 FT /evidence="ECO:0007829|PDB:1ITX" FT STRAND 45..51 FT /evidence="ECO:0007829|PDB:1ITX" FT HELIX 52..55 FT /evidence="ECO:0007829|PDB:1ITX" FT TURN 56..58 FT /evidence="ECO:0007829|PDB:1ITX" FT HELIX 62..64 FT /evidence="ECO:0007829|PDB:1ITX" FT STRAND 71..80 FT /evidence="ECO:0007829|PDB:1ITX" FT STRAND 85..88 FT /evidence="ECO:0007829|PDB:1ITX" FT STRAND 97..100 FT /evidence="ECO:0007829|PDB:1ITX" FT STRAND 116..120 FT /evidence="ECO:0007829|PDB:1ITX" FT HELIX 122..126 FT /evidence="ECO:0007829|PDB:1ITX" FT STRAND 134..137 FT /evidence="ECO:0007829|PDB:1ITX" FT HELIX 140..148 FT /evidence="ECO:0007829|PDB:1ITX" FT TURN 149..151 FT /evidence="ECO:0007829|PDB:1ITX" FT STRAND 156..162 FT /evidence="ECO:0007829|PDB:1ITX" FT STRAND 164..166 FT /evidence="ECO:0007829|PDB:1ITX" FT HELIX 170..174 FT /evidence="ECO:0007829|PDB:1ITX" FT HELIX 177..194 FT /evidence="ECO:0007829|PDB:1ITX" FT STRAND 197..202 FT /evidence="ECO:0007829|PDB:1ITX" FT STRAND 206..208 FT /evidence="ECO:0007829|PDB:1ITX" FT HELIX 220..242 FT /evidence="ECO:0007829|PDB:1ITX" FT STRAND 247..252 FT /evidence="ECO:0007829|PDB:1ITX" FT HELIX 256..260 FT /evidence="ECO:0007829|PDB:1ITX" FT HELIX 264..270 FT /evidence="ECO:0007829|PDB:1ITX" FT STRAND 271..276 FT /evidence="ECO:0007829|PDB:1ITX" FT STRAND 286..288 FT /evidence="ECO:0007829|PDB:1ITX" FT HELIX 299..303 FT /evidence="ECO:0007829|PDB:1ITX" FT TURN 307..311 FT /evidence="ECO:0007829|PDB:1ITX" FT HELIX 314..324 FT /evidence="ECO:0007829|PDB:1ITX" FT HELIX 328..330 FT /evidence="ECO:0007829|PDB:1ITX" FT STRAND 331..344 FT /evidence="ECO:0007829|PDB:1ITX" FT HELIX 348..351 FT /evidence="ECO:0007829|PDB:1ITX" FT STRAND 357..359 FT /evidence="ECO:0007829|PDB:1ITX" FT STRAND 364..366 FT /evidence="ECO:0007829|PDB:1ITX" FT STRAND 369..371 FT /evidence="ECO:0007829|PDB:1ITX" FT HELIX 372..378 FT /evidence="ECO:0007829|PDB:1ITX" FT TURN 379..381 FT /evidence="ECO:0007829|PDB:1ITX" FT STRAND 385..390 FT /evidence="ECO:0007829|PDB:1ITX" FT TURN 391..394 FT /evidence="ECO:0007829|PDB:1ITX" FT STRAND 395..400 FT /evidence="ECO:0007829|PDB:1ITX" FT TURN 401..403 FT /evidence="ECO:0007829|PDB:1ITX" FT STRAND 406..408 FT /evidence="ECO:0007829|PDB:1ITX" FT HELIX 412..425 FT /evidence="ECO:0007829|PDB:1ITX" FT STRAND 429..433 FT /evidence="ECO:0007829|PDB:1ITX" FT HELIX 435..438 FT /evidence="ECO:0007829|PDB:1ITX" FT HELIX 442..450 FT /evidence="ECO:0007829|PDB:1ITX" FT STRAND 564..571 FT /evidence="ECO:0007829|PDB:1K85" FT STRAND 576..581 FT /evidence="ECO:0007829|PDB:1K85" FT STRAND 587..611 FT /evidence="ECO:0007829|PDB:1K85" FT STRAND 619..628 FT /evidence="ECO:0007829|PDB:1K85" FT TURN 629..631 FT /evidence="ECO:0007829|PDB:1K85" FT STRAND 640..643 FT /evidence="ECO:0007829|PDB:1K85" FT STRAND 658..662 FT /evidence="ECO:0007829|PDB:1ED7" FT STRAND 668..670 FT /evidence="ECO:0007829|PDB:1ED7" FT STRAND 673..675 FT /evidence="ECO:0007829|PDB:1ED7" FT STRAND 681..683 FT /evidence="ECO:0007829|PDB:1ED7" FT TURN 693..695 FT /evidence="ECO:0007829|PDB:1ED7" SQ SEQUENCE 699 AA; 73678 MW; AC7C9B22E2987643 CRC64; MINLNKHTAF KKTAKFFLGL SLLLSVIVPS FALQPATAEA ADSYKIVGYY PSWAAYGRNY NVADIDPTKV THINYAFADI CWNGIHGNPD PSGPNPVTWT CQNEKSQTIN VPNGTIVLGD PWIDTGKTFA GDTWDQPIAG NINQLNKLKQ TNPNLKTIIS VGGWTWSNRF SDVAATAATR EVFANSAVDF LRKYNFDGVD LDWEYPVSGG LDGNSKRPED KQNYTLLLSK IREKLDAAGA VDGKKYLLTI ASGASATYAA NTELAKIAAI VDWINIMTYD FNGAWQKISA HNAPLNYDPA ASAAGVPDAN TFNVAAGAQG HLDAGVPAAK LVLGVPFYGR GWDGCAQAGN GQYQTCTGGS SVGTWEAGSF DFYDLEANYI NKNGYTRYWN DTAKVPYLYN ASNKRFISYD DAESVGYKTA YIKSKGLGGA MFWELSGDRN KTLQNKLKAD LPTGGTVPPV DTTAPSVPGN ARSTGVTANS VTLAWNASTD NVGVTGYNVY NGANLATSVT GTTATISGLT AGTSYTFTIK AKDAAGNLSA ASNAVTVSTT AQPGGDTQAP TAPTNLASTA QTTSSITLSW TASTDNVGVT GYDVYNGTAL ATTVTGTTAT ISGLAADTSY TFTVKAKDAA GNVSAASNAV SVKTAAETTN PGVSAWQVNT AYTAGQLVTY NGKTYKCLQP HTSLAGWEPS NVPALWQLQ //