ID   CHIQ_TOBAC              Reviewed;         253 AA.
AC   P17514;
DT   01-AUG-1990, integrated into UniProtKB/Swiss-Prot.
DT   01-AUG-1990, sequence version 1.
DT   25-MAY-2022, entry version 110.
DE   RecName: Full=Acidic endochitinase Q;
DE            EC=3.2.1.14;
DE   AltName: Full=Pathogenesis-related protein Q;
DE            Short=PR-Q;
DE   Flags: Precursor;
OS   Nicotiana tabacum (Common tobacco).
OC   Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC   Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae;
OC   asterids; lamiids; Solanales; Solanaceae; Nicotianoideae; Nicotianeae;
OC   Nicotiana.
OX   NCBI_TaxID=4097;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA], AND PARTIAL PROTEIN SEQUENCE.
RC   STRAIN=cv. Xanthi NC;
RX   PubMed=2296608; DOI=10.1073/pnas.87.1.98;
RA   Payne G., Ahl P., Moyer M., Harper A., Beck J., Meins F. Jr., Ryals J.;
RT   "Isolation of complementary DNA clones encoding pathogenesis-related
RT   proteins P and Q, two acidic chitinases from tobacco.";
RL   Proc. Natl. Acad. Sci. U.S.A. 87:98-102(1990).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RC   STRAIN=cv. Samsun; TISSUE=Leaf;
RX   PubMed=2131096; DOI=10.1094/mpmi-3-252;
RA   Linthorst H.J.M., van Loon L.C., van Rossum C.M.A., Mayer A., Bol J.F.,
RA   van Roekel J., Meulenhof J., Conelissen B.J.C.;
RT   "Analysis of acidic and basic chitinases from tobacco and petunia and their
RT   constitutive expression in transgenic tobacco.";
RL   Mol. Plant Microbe Interact. 3:252-258(1990).
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   -!- SUBCELLULAR LOCATION: Secreted. Note=Extracellular fluid from leaves.
CC   -!- INDUCTION: By TMV infection.
CC   -!- SIMILARITY: Belongs to the glycosyl hydrolase 19 family. Chitinase
CC       class I subfamily. {ECO:0000305}.
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DR   EMBL; M29868; AAA34107.1; -; mRNA.
DR   EMBL; X51425; CAA35789.1; -; mRNA.
DR   PIR; B34801; B34801.
DR   PIR; S20738; S20738.
DR   AlphaFoldDB; P17514; -.
DR   SMR; P17514; -.
DR   STRING; 4097.P17514; -.
DR   CAZy; GH19; Glycoside Hydrolase Family 19.
DR   Proteomes; UP000084051; Unplaced.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
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:0050832; P:defense response to fungus; IBA:GO_Central.
DR   GO; GO:0000272; P:polysaccharide catabolic process; IEA:UniProtKB-KW.
DR   InterPro; IPR016283; Glyco_hydro_19.
DR   InterPro; IPR000726; Glyco_hydro_19_cat.
DR   InterPro; IPR023346; Lysozyme-like_dom_sf.
DR   Pfam; PF00182; Glyco_hydro_19; 1.
DR   PIRSF; PIRSF001060; Endochitinase; 1.
DR   SUPFAM; SSF53955; SSF53955; 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; Direct protein sequencing;
KW   Disulfide bond; Glycosidase; Hydrolase; Pathogenesis-related protein;
KW   Plant defense; Polysaccharide degradation; Reference proteome; Secreted;
KW   Signal.
FT   SIGNAL          1..24
FT   CHAIN           25..253
FT                   /note="Acidic endochitinase Q"
FT                   /id="PRO_0000005337"
FT   ACT_SITE        92
FT                   /note="Proton donor"
FT                   /evidence="ECO:0000250|UniProtKB:P29022"
FT   DISULFID        212..244
FT                   /evidence="ECO:0000250"
FT   VARIANT         54
FT                   /note="Y -> F (in strain: cv. Samsun)"
SQ   SEQUENCE   253 AA;  27633 MW;  0DED41DEA99CE196 CRC64;
     MEFSGSPMAL FCCVFFLFLT GSLAQGIGSI VTSDLFNEML KNRNDGRCPA NGFYTYDAFI
     AAANSFPGFG TTGDDTARRK EIAAFFGQTS HETTGGSLSA EPFTGGYCFV RQNDQSDRYY
     GRGPIQLTNR NNYEKAGTAI GQELVNNPDL VATDATISFK TAIWFWMTPQ DNKPSSHDVI
     IGRWTPSAAD QAANRVPGYG VITNIINGGI ECGIGRNDAV EDRIGYYRRY CGMLNVAPGE
     NLDCYNQRNF GQG