ID   VM3FA_VIPAA             Reviewed;          15 AA.
AC   P0C8I7;
DT   25-NOV-2008, integrated into UniProtKB/Swiss-Prot.
DT   25-NOV-2008, sequence version 1.
DT   03-AUG-2022, entry version 29.
DE   RecName: Full=Factor X-activator 1 heavy chain;
DE            Short=VAFXA-I HC;
DE            EC=3.4.24.-;
DE   AltName: Full=Snake venom metalloproteinase;
DE            Short=SVMP;
DE   Flags: Fragment;
OS   Vipera ammodytes ammodytes (Western sand viper).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC   Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Toxicofera;
OC   Serpentes; Colubroidea; Viperidae; Viperinae; Vipera.
OX   NCBI_TaxID=8705;
RN   [1]
RP   PROTEIN SEQUENCE, FUNCTION, AND CATALYTIC ACTIVITY.
RC   TISSUE=Venom;
RX   PubMed=18760294; DOI=10.1016/j.toxicon.2008.07.015;
RA   Leonardi A., Fox J.W., Trampus-Bakija A., Krizaj I.;
RT   "Two coagulation factor X activators from Vipera a. ammodytes venom with
RT   potential to treat patients with dysfunctional factors IXa or VIIa.";
RL   Toxicon 52:628-637(2008).
CC   -!- FUNCTION: Catalytic subunit of blood coagulation factor X-activating
CC       enzyme. Activates coagulation factor X (F10) in a calcium-dependent
CC       manner by cleaving at the '234-Arg-|-Ile-235' site. Weakly hydrolyzes
CC       insulin B chain (by cleaving at the '27-Asn-|-Gln-28' and '44-Gly-|-
CC       Glu-45' sites), fibrinogen and some components of the extracellular
CC       matrix in vitro. {ECO:0000269|PubMed:18760294}.
CC   -!- COFACTOR:
CC       Name=Zn(2+); Xref=ChEBI:CHEBI:29105; Evidence={ECO:0000250};
CC       Note=Binds 1 zinc ion per subunit. {ECO:0000250};
CC   -!- SUBUNIT: Heterotrimer; disulfide-linked. The heterotrimer consists of 1
CC       heavy chain and 2 light chains (lectins): LC1 (AC P0C8J2) and LC2 (AC
CC       P0C8J3).
CC   -!- SUBCELLULAR LOCATION: Secreted.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC   -!- PTM: N-glycosylated.
CC   -!- MISCELLANEOUS: Does not activate prothrombin or plasminogen.
CC   -!- SIMILARITY: Belongs to the venom metalloproteinase (M12B) family. P-III
CC       subfamily. P-IIId sub-subfamily. {ECO:0000305}.
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DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR   GO; GO:0008237; F:metallopeptidase 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; Calcium;
KW   Direct protein sequencing; Disulfide bond; Glycoprotein;
KW   Hemostasis impairing toxin; Hydrolase; Metal-binding; Metalloprotease;
KW   Protease; Secreted; Toxin; Zinc; Zymogen.
FT   CHAIN           1..>15
FT                   /note="Factor X-activator 1 heavy chain"
FT                   /id="PRO_0000355227"
FT   DOMAIN          11..>15
FT                   /note="Peptidase M12B"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00276"
FT   BINDING         11
FT                   /ligand="Ca(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29108"
FT                   /evidence="ECO:0000250"
FT   BINDING         13
FT                   /ligand="Ca(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29108"
FT                   /evidence="ECO:0000250"
FT   BINDING         15
FT                   /ligand="Ca(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29108"
FT                   /evidence="ECO:0000250"
FT   NON_TER         15
SQ   SEQUENCE   15 AA;  1643 MW;  D5429F469CD5A435 CRC64;
     LVSVSPAFNG NYFVE