ID   VSPF_CERCE              Reviewed;          33 AA.
AC   Q9PS28;
DT   10-JUL-2007, integrated into UniProtKB/Swiss-Prot.
DT   01-MAY-2000, sequence version 1.
DT   03-AUG-2022, entry version 46.
DE   RecName: Full=Thrombin-like enzyme RP34;
DE            Short=SVTLE;
DE            EC=3.4.21.74;
DE   AltName: Full=Fibrinogen-clotting enzyme;
DE   AltName: Full=Snake venom serine protease;
DE            Short=SVSP;
DE   AltName: Full=Venombin A;
DE   Flags: Fragment;
OS   Cerastes cerastes (Horned desert viper).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC   Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Toxicofera;
OC   Serpentes; Colubroidea; Viperidae; Viperinae; Cerastes.
OX   NCBI_TaxID=8697;
RN   [1]
RP   PROTEIN SEQUENCE, FUNCTION, BIOPHYSICOCHEMICAL PROPERTIES, AND SUBUNIT.
RC   TISSUE=Venom;
RX   PubMed=1485336; DOI=10.1016/0041-0101(92)90515-7;
RA   Laraba-Djebari F., Martin-Eauclaire M.-F., Marchot P.;
RT   "A fibrinogen-clotting serine proteinase from Cerastes cerastes (horned
RT   viper) venom with arginine-esterase and amidase activities. Purification,
RT   characterization and kinetic parameter determination.";
RL   Toxicon 30:1399-1410(1992).
CC   -!- FUNCTION: Thrombin-like snake venom serine protease that displays
CC       clotting activity on fibrinogen. Shows both arginine-ester hydrolase
CC       and amidase activities on synthetic substrates. Also shows proteolytic
CC       activity toward casein. {ECO:0000269|PubMed:1485336}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=Selective cleavage of Arg-|-Xaa bond in fibrinogen, to form
CC         fibrin, and release fibrinopeptide A. The specificity of further
CC         degradation of fibrinogen varies with species origin of the enzyme.;
CC         EC=3.4.21.74;
CC   -!- BIOPHYSICOCHEMICAL PROPERTIES:
CC       Kinetic parameters:
CC         KM=65 nM for CBS 34-47 {ECO:0000269|PubMed:1485336};
CC   -!- SUBUNIT: Homodimer. {ECO:0000269|PubMed:1485336}.
CC   -!- SUBCELLULAR LOCATION: Secreted.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC   -!- SIMILARITY: Belongs to the peptidase S1 family. Snake venom subfamily.
CC       {ECO:0000255|PROSITE-ProRule:PRU00274}.
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DR   PIR; A44181; A44181.
DR   SABIO-RK; Q9PS28; -.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0008236; F:serine-type peptidase activity; IEA:UniProtKB-KW.
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   Blood coagulation cascade activating toxin; Direct protein sequencing;
KW   Hemostasis impairing toxin; Hydrolase; Protease; Secreted; Serine protease;
KW   Toxin.
FT   CHAIN           1..>33
FT                   /note="Thrombin-like enzyme RP34"
FT                   /id="PRO_0000294991"
FT   DOMAIN          1..>33
FT                   /note="Peptidase S1"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00274"
FT   NON_TER         33
SQ   SEQUENCE   33 AA;  3786 MW;  123F8467054D32E3 CRC64;
     VIGGDEXDIN EHRSLALMYX SWSHRFIXXG XLI