ID   VSP3_CROAT              Reviewed;          15 AA.
AC   Q9PRW2;
DT   05-APR-2011, integrated into UniProtKB/Swiss-Prot.
DT   01-MAY-2000, sequence version 1.
DT   03-AUG-2022, entry version 34.
DE   RecName: Full=Alpha-fibrinogenase A3;
DE            EC=3.4.21.-;
DE   AltName: Full=Snake venom serine protease;
DE            Short=SVSP;
DE   Flags: Fragment;
OS   Crotalus atrox (Western diamondback rattlesnake).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC   Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Toxicofera;
OC   Serpentes; Colubroidea; Viperidae; Crotalinae; Crotalus.
OX   NCBI_TaxID=8730;
RN   [1]
RP   PROTEIN SEQUENCE, FUNCTION, ACTIVITY REGULATION, SUBUNIT, SUBCELLULAR
RP   LOCATION, AND TISSUE SPECIFICITY.
RC   TISSUE=Venom;
RX   PubMed=8024586; DOI=10.1006/bbrc.1994.1861;
RA   Hung C.C., Chiou S.H.;
RT   "Isolation of multiple isoforms of alpha-fibrinogenase from the Western
RT   diamondback rattlesnake, Crotalus atrox: N-terminal sequence homology with
RT   ancrod, an antithrombotic agent from Malayan viper.";
RL   Biochem. Biophys. Res. Commun. 201:1414-1423(1994).
RN   [2]
RP   PROTEIN SEQUENCE, AND IDENTIFICATION BY MASS SPECTROMETRY.
RC   TISSUE=Venom;
RX   PubMed=19371136; DOI=10.1021/pr900249q;
RA   Calvete J.J., Fasoli E., Sanz L., Boschetti E., Righetti P.G.;
RT   "Exploring the venom proteome of the western diamondback rattlesnake,
RT   Crotalus atrox, via snake venomics and combinatorial peptide ligand library
RT   approaches.";
RL   J. Proteome Res. 8:3055-3067(2009).
CC   -!- FUNCTION: Snake venom serine protease that cleaves fibrinogen Aalpha
CC       chain (FGA), partially cleaves Bbeta chain (FGB) and has no activity on
CC       gamma chain. Is less potent than A1 and A2 alpha-fibrinogenases.
CC       {ECO:0000269|PubMed:8024586}.
CC   -!- ACTIVITY REGULATION: Inhibited by PMSF, bovine aprotinin (APR), soybean
CC       trypsin inhibitor (STI), and high temperature (85 degrees Celsius). Is
CC       not inhibited by EDTA, and beta-mercaptoethanol.
CC       {ECO:0000269|PubMed:8024586}.
CC   -!- SUBUNIT: Monomer. {ECO:0000269|PubMed:8024586}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:8024586}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC       {ECO:0000269|PubMed:8024586}.
CC   -!- SIMILARITY: Belongs to the peptidase S1 family. Snake venom subfamily.
CC       {ECO:0000255|PROSITE-ProRule:PRU00274}.
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DR   GO; GO:0005615; C:extracellular space; IDA:UniProtKB.
DR   GO; GO:0004252; F:serine-type endopeptidase activity; IDA:UniProtKB.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR   GO; GO:0006508; P:proteolysis; IEA:UniProtKB-KW.
PE   1: Evidence at protein level;
KW   Direct protein sequencing; Disulfide bond; Fibrinogenolytic toxin;
KW   Hemostasis impairing toxin; Hydrolase; Protease; Secreted; Serine protease;
KW   Toxin.
FT   CHAIN           1..>15
FT                   /note="Alpha-fibrinogenase A3"
FT                   /id="PRO_0000406906"
FT   DISULFID        7..?
FT   NON_TER         15
SQ   SEQUENCE   15 AA;  1656 MW;  03EFE10227D52FDA CRC64;
     VIGGDECNIN EHRSL