ID   VKT_SISCA               Reviewed;         152 AA.
AC   A5X2X1;
DT   16-JUN-2009, integrated into UniProtKB/Swiss-Prot.
DT   10-JUL-2007, sequence version 1.
DT   25-MAY-2022, entry version 49.
DE   RecName: Full=Fused toxin protein;
DE   Flags: Precursor;
OS   Sistrurus catenatus edwardsii (Desert massasauga) (Crotalophorus
OS   edwardsii).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC   Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Toxicofera;
OC   Serpentes; Colubroidea; Viperidae; Crotalinae; Sistrurus.
OX   NCBI_TaxID=8762;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
RC   TISSUE=Venom gland;
RX   PubMed=18096037; DOI=10.1186/1471-2199-8-115;
RA   Pahari S., Mackessy S.P., Kini R.M.;
RT   "The venom gland transcriptome of the Desert Massasauga rattlesnake
RT   (Sistrurus catenatus edwardsii): towards an understanding of venom
RT   composition among advanced snakes (Superfamily Colubroidea).";
RL   BMC Mol. Biol. 8:115-115(2007).
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000250}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC   -!- MISCELLANEOUS: May code either for a precursor which is processed to
CC       form two individual classes of venom proteins (Kunitz/BPTI and waprin)
CC       or a novel toxin with two distinct domains and having a new biological
CC       function.
CC   -!- SIMILARITY: Belongs to the venom Kunitz-type family. {ECO:0000305}.
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DR   EMBL; DQ464286; ABG27009.1; -; mRNA.
DR   AlphaFoldDB; A5X2X1; -.
DR   SMR; A5X2X1; -.
DR   MEROPS; I02.062; -.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0004867; F:serine-type endopeptidase inhibitor activity; IEA:UniProtKB-KW.
DR   CDD; cd00109; KU; 1.
DR   Gene3D; 4.10.410.10; -; 1.
DR   Gene3D; 4.10.75.10; -; 1.
DR   InterPro; IPR036645; Elafin-like_sf.
DR   InterPro; IPR002223; Kunitz_BPTI.
DR   InterPro; IPR036880; Kunitz_BPTI_sf.
DR   InterPro; IPR020901; Prtase_inh_Kunz-CS.
DR   InterPro; IPR008197; WAP_dom.
DR   Pfam; PF00014; Kunitz_BPTI; 1.
DR   Pfam; PF00095; WAP; 1.
DR   PRINTS; PR00759; BASICPTASE.
DR   SMART; SM00131; KU; 1.
DR   SMART; SM00217; WAP; 1.
DR   SUPFAM; SSF57256; SSF57256; 1.
DR   SUPFAM; SSF57362; SSF57362; 1.
DR   PROSITE; PS00280; BPTI_KUNITZ_1; 1.
DR   PROSITE; PS50279; BPTI_KUNITZ_2; 1.
DR   PROSITE; PS51390; WAP; 1.
PE   2: Evidence at transcript level;
KW   Disulfide bond; Protease inhibitor; Pyrrolidone carboxylic acid; Secreted;
KW   Serine protease inhibitor; Signal.
FT   SIGNAL          1..24
FT                   /evidence="ECO:0000250"
FT   CHAIN           25..152
FT                   /note="Fused toxin protein"
FT                   /id="PRO_0000376906"
FT   DOMAIN          31..81
FT                   /note="BPTI/Kunitz inhibitor"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00031"
FT   DOMAIN          81..127
FT                   /note="WAP; atypical"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00722"
FT   SITE            41..42
FT                   /note="Reactive bond for trypsin"
FT                   /evidence="ECO:0000250"
FT   MOD_RES         25
FT                   /note="Pyrrolidone carboxylic acid"
FT                   /evidence="ECO:0000250"
FT   DISULFID        31..81
FT                   /evidence="ECO:0000250"
FT   DISULFID        40..64
FT                   /evidence="ECO:0000250"
FT   DISULFID        56..77
FT                   /evidence="ECO:0000250"
FT   DISULFID        88..115
FT                   /evidence="ECO:0000250"
FT   DISULFID        102..114
FT                   /evidence="ECO:0000250"
FT   DISULFID        108..123
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   152 AA;  16710 MW;  BA85FA92A14997B6 CRC64;
     MSSGGLLLLL GFLTLWAELT PVSGQDPPRF CSLPAETGEC RGRIPRFYYN SASKQCEQFF
     YSGCGGNANN FETKDQCHYT CVEKPGVCPP RPQQQGQEGK NCENDWKCPG QQKCCRYRGK
     TECKDAVFEK FASTTRTPTS IGSTPVGSSV PT