ID   KTXA_KLULA              Reviewed;        1146 AA.
AC   P09805;
DT   01-JUL-1989, integrated into UniProtKB/Swiss-Prot.
DT   01-JUL-1989, sequence version 1.
DT   27-MAR-2024, entry version 149.
DE   RecName: Full=Killer toxin subunits alpha/beta;
DE   AltName: Full=RF2 protein;
DE   Contains:
DE     RecName: Full=Killer toxin subunit alpha;
DE   Contains:
DE     RecName: Full=Killer toxin subunit beta;
DE              EC=3.2.1.14;
DE     AltName: Full=Endochitinase;
DE   Flags: Precursor;
OS   Kluyveromyces lactis (strain ATCC 8585 / CBS 2359 / DSM 70799 / NBRC 1267 /
OS   NRRL Y-1140 / WM37) (Yeast) (Candida sphaerica).
OG   Plasmid pGKl-1.
OC   Eukaryota; Fungi; Dikarya; Ascomycota; Saccharomycotina; Saccharomycetes;
OC   Saccharomycetales; Saccharomycetaceae; Kluyveromyces.
OX   NCBI_TaxID=284590;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC   STRAIN=ATCC 76492 / CBS 2359/152 / CLIB 210;
RX   DOI=10.1007/BF00436963;
RA   Sor F., Fukuhara H.;
RT   "Structure of a linear plasmid of the yeast Kluyveromyces lactis; compact
RT   organization of the killer genome.";
RL   Curr. Genet. 9:147-155(1985).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC   STRAIN=ATCC 8585 / CBS 2359 / DSM 70799 / NBRC 1267 / NRRL Y-1140 /
RC   WM37;
RX   PubMed=6473099; DOI=10.1093/nar/12.15.6011;
RA   Stark M.J.R., Mileham A.J., Romanos M.A., Boyd A.;
RT   "Nucleotide sequence and transcription analysis of a linear DNA plasmid
RT   associated with the killer character of the yeast Kluyveromyces lactis.";
RL   Nucleic Acids Res. 12:6011-6030(1984).
RN   [3]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC   STRAIN=ATCC 52735 / 2105-1D;
RX   PubMed=6387625; DOI=10.1093/nar/12.19.7581;
RA   Hishinuma F., Nakamura K., Hirai K., Nishizawa R., Gunge N., Maeda T.;
RT   "Cloning and nucleotide sequences of the linear DNA killer plasmids from
RT   yeast.";
RL   Nucleic Acids Res. 12:7581-7597(1984).
RN   [4]
RP   IDENTIFICATION OF PROTEIN, AND PROTEIN SEQUENCE OF 30-44 AND 895-916.
RX   PubMed=3758030; DOI=10.1002/j.1460-2075.1986.tb04455.x;
RA   Stark M.J.R., Boyd A.;
RT   "The killer toxin of Kluyveromyces lactis: characterization of the toxin
RT   subunits and identification of the genes which encode them.";
RL   EMBO J. 5:1995-2002(1986).
RN   [5]
RP   SIMILARITY TO CHITINASE OF ALPHA-SUBUNIT.
RX   PubMed=2342564; DOI=10.1038/345299b0;
RA   Bradshaw H.D. Jr.;
RT   "Killer toxins.";
RL   Nature 345:299-299(1990).
RN   [6]
RP   CHITINASE ACTIVITY OF ALPHA-SUBUNIT.
RX   PubMed=2070799; DOI=10.1111/j.1432-1033.1991.tb16147.x;
RA   Butler A.R., O'Donnell R.W., Martin V.J., Gooday G.W., Stark M.J.R.;
RT   "Kluyveromyces lactis toxin has an essential chitinase activity.";
RL   Eur. J. Biochem. 199:483-488(1991).
CC   -!- FUNCTION: The alpha subunit is a potent exochitinase. Along with the
CC       beta subunit it plays a role in the initial interaction of the toxin
CC       with sensitive cells and allow the gamma subunit (the active toxin) to
CC       gain entry into the cell.
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   -!- SUBUNIT: The killer toxin is composed of three subunits: alpha, beta
CC       and gamma.
CC   -!- PTM: RF2 is potentially split by membrane-bound basic amino acid-
CC       specific peptidase to yield the alpha and beta subunits.
CC   -!- SIMILARITY: Belongs to the glycosyl hydrolase 18 family.
CC       {ECO:0000255|PROSITE-ProRule:PRU01258}.
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DR   EMBL; X07127; CAA30137.1; -; Genomic_DNA.
DR   EMBL; X00762; CAA25334.1; -; Genomic_DNA.
DR   EMBL; X01095; CAA25569.1; -; Genomic_DNA.
DR   PIR; S07915; S07915.
DR   AlphaFoldDB; P09805; -.
DR   SMR; P09805; -.
DR   STRING; 284590.P09805; -.
DR   CAZy; CBM18; Carbohydrate-Binding Module Family 18.
DR   CAZy; CBM50; Carbohydrate-Binding Module Family 50.
DR   CAZy; GH18; Glycoside Hydrolase Family 18.
DR   CLAE; CHI18A_KLULA; -.
DR   PaxDb; 284590-P09805; -.
DR   InParanoid; P09805; -.
DR   GO; GO:0008061; F:chitin binding; IEA:UniProtKB-KW.
DR   GO; GO:0004568; F:chitinase activity; IEA:UniProtKB-EC.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR   GO; GO:0006032; P:chitin catabolic process; IEA:UniProtKB-KW.
DR   GO; GO:0000272; P:polysaccharide catabolic process; IEA:UniProtKB-KW.
DR   CDD; cd00035; ChtBD1; 1.
DR   CDD; cd02878; GH18_zymocin_alpha; 1.
DR   CDD; cd00118; LysM; 1.
DR   Gene3D; 3.10.50.10; -; 1.
DR   Gene3D; 3.30.60.10; Endochitinase-like; 1.
DR   Gene3D; 3.20.20.80; Glycosidases; 1.
DR   Gene3D; 3.10.350.10; LysM domain; 1.
DR   InterPro; IPR001002; Chitin-bd_1.
DR   InterPro; IPR018371; Chitin-binding_1_CS.
DR   InterPro; IPR011583; Chitinase_II.
DR   InterPro; IPR029070; Chitinase_insertion_sf.
DR   InterPro; IPR036861; Endochitinase-like_sf.
DR   InterPro; IPR001223; Glyco_hydro18_cat.
DR   InterPro; IPR001579; Glyco_hydro_18_chit_AS.
DR   InterPro; IPR017853; Glycoside_hydrolase_SF.
DR   InterPro; IPR018392; LysM_dom.
DR   InterPro; IPR036779; LysM_dom_sf.
DR   PANTHER; PTHR47700:SF2; CHITINASE; 1.
DR   PANTHER; PTHR47700; V CHITINASE, PUTATIVE (AFU_ORTHOLOGUE AFUA_6G13720)-RELATED; 1.
DR   Pfam; PF00187; Chitin_bind_1; 1.
DR   Pfam; PF00704; Glyco_hydro_18; 1.
DR   Pfam; PF01476; LysM; 1.
DR   SMART; SM00270; ChtBD1; 1.
DR   SMART; SM00636; Glyco_18; 1.
DR   SMART; SM00257; LysM; 1.
DR   SUPFAM; SSF51445; (Trans)glycosidases; 1.
DR   SUPFAM; SSF54556; Chitinase insertion domain; 1.
DR   SUPFAM; SSF54106; LysM domain; 1.
DR   SUPFAM; SSF57016; Plant lectins/antimicrobial peptides; 1.
DR   PROSITE; PS00026; CHIT_BIND_I_1; 1.
DR   PROSITE; PS50941; CHIT_BIND_I_2; 1.
DR   PROSITE; PS01095; GH18_1; 1.
DR   PROSITE; PS51910; GH18_2; 1.
DR   PROSITE; PS51782; LYSM; 1.
PE   1: Evidence at protein level;
KW   Carbohydrate metabolism; Chitin degradation; Chitin-binding;
KW   Cleavage on pair of basic residues; Direct protein sequencing;
KW   Disulfide bond; Glycoprotein; Glycosidase; Hydrolase; Plasmid;
KW   Polysaccharide degradation; Repeat; Signal; Toxin.
FT   SIGNAL          1..17
FT                   /evidence="ECO:0000255"
FT   PROPEP          18..29
FT                   /evidence="ECO:0000255"
FT                   /id="PRO_0000011938"
FT   CHAIN           30..892
FT                   /note="Killer toxin subunit alpha"
FT                   /evidence="ECO:0000305"
FT                   /id="PRO_0000011939"
FT   CHAIN           895..1146
FT                   /note="Killer toxin subunit beta"
FT                   /evidence="ECO:0000305"
FT                   /id="PRO_0000011940"
FT   DOMAIN          205..234
FT                   /note="LysM 1"
FT   DOMAIN          254..303
FT                   /note="LysM 2"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01118"
FT   DOMAIN          316..372
FT                   /note="Chitin-binding type-1"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00261"
FT   DOMAIN          383..735
FT                   /note="GH18"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01258"
FT   ACT_SITE        495
FT                   /note="Proton donor"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01258"
FT   BINDING         424
FT                   /ligand="chitin"
FT                   /ligand_id="ChEBI:CHEBI:17029"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01258"
FT   BINDING         447..450
FT                   /ligand="chitin"
FT                   /ligand_id="ChEBI:CHEBI:17029"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01258"
FT   BINDING         496
FT                   /ligand="chitin"
FT                   /ligand_id="ChEBI:CHEBI:17029"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01258"
FT   BINDING         562..565
FT                   /ligand="chitin"
FT                   /ligand_id="ChEBI:CHEBI:17029"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01258"
FT   BINDING         707
FT                   /ligand="chitin"
FT                   /ligand_id="ChEBI:CHEBI:17029"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01258"
FT   CARBOHYD        771
FT                   /note="N-linked (GlcNAc...) asparagine"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        858
FT                   /note="N-linked (GlcNAc...) asparagine"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        868
FT                   /note="N-linked (GlcNAc...) asparagine"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        876
FT                   /note="N-linked (GlcNAc...) asparagine"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        1117
FT                   /note="N-linked (GlcNAc...) asparagine"
FT                   /evidence="ECO:0000255"
FT   DISULFID        319..338
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00261"
FT   DISULFID        332..344
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00261"
FT   DISULFID        337..351
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00261"
FT   DISULFID        366..370
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00261"
SQ   SEQUENCE   1146 AA;  128937 MW;  BF4B1764EB465DE6 CRC64;
     MNIFYIFLFL LSFVQGLEHT HRRGSLVKRA VCYDTDQVPL NIFFGYNRAD KTDSNKNMAL
     NIFNVFRGFL AGEGGESFYN SNGNVYGFMW VGSMVHNRGF KDNILPIMEN EVKNYGIPKT
     LYLEYDGGGD PMKSFGIILD TTSRDTVVKA AKLWSQGKKL NSYEGSKNYQ ATACYLSYAY
     RKPIVNDNFV GTCDYFTLES GKTPADQSGI NGESLQGYNP NLDFSKLSAG QPICKTIGNP
     PNFKPSKNSD GSCKTYKVSS GESCSSIAVK YYPLSLNDIE NYNKGNYGWK GCSSLQKDYN
     LCVSDGSAPR PVSNPIAECG PLAPGEKYNA KCPLNACCSE FGFCGLTKDY CDKKSSTTGA
     PGTDGCFSNC GYGSTSNVKS STFKKIAYWL DAKDKLAMDP KNIPNGPYDI LHYAFVNINS
     DFSIDDSAFS KSAFLKVTSS KKIPSFGGWD FSTSPSTYTI FRNAVKTDQN RNTFANNLIN
     FMNKYNLDGI DLDWEYPGAP DIPDIPADDS SSGSNYLTFL KLLKGKMPSG KTLSIAIPSS
     YWYLKNFPIS DIQNTVDYMV YMTYDIHGIW EYGKANSYIN CHTPRKEIED AIKMLDKAGV
     KFNKVFGGVA NYGRSYKMVN TNCYNYGCGF QREGGNSRDM TNTPGVLSDS EIIDIDSSDK
     KNDRWVDTNT DCIFMKYDGN SVVSWPKSRY DLEDMFKNYG FAGTSLWAAN YFKHDEWKND
     EDDNNDDTED PFDEENVYFD VYDCKNKAGY DLDNPVYGCR LETAINIIIW NGTESVNTVL
     NILNDYDNYI KYYEALTRAH YDSVMEKYEK WLFEEDGYYT YYTDVDGDDI IITPPDKKKR
     DYIQEKYSFE KEFMMSQNMT ELTEIKVNKT INFMLNGTSL AVKEYNNEKV LYKRGDIPPP
     GSNNRLIRNS IILDKDKEAA IASFKQYSGI ELSKDSFVQR DKDKKFDLNG KHYTFMHSTI
     LNAIVLFPNV LTNIDSDYIH HISDLIEQAH NSLGNESPDN IYEVLESVVV FMSVSEIADY
     TYTEGKKIKE KYDKMKKTMI VGIILGIIGG LSLFLGPIGI ATSVLADFAL LGADAAINGE
     LNPSDLAFAL AGLFLPVFAS LGKTFKFAEA LQKININKSK NFDNLNEFEK IRFFRSKLGK
     VKMCGS
//