PA2B_BITCA
ID PA2B_BITCA Reviewed; 121 AA.
AC P00622;
DT 21-JUL-1986, integrated into UniProtKB/Swiss-Prot.
DT 21-JUL-1986, sequence version 1.
DT 03-AUG-2022, entry version 107.
DE RecName: Full=Basic phospholipase A2 caudoxin;
DE Short=svPLA2;
DE EC=3.1.1.4;
DE AltName: Full=Phosphatidylcholine 2-acylhydrolase;
OS Bitis caudalis (Horned adder) (Horned viper).
OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Toxicofera;
OC Serpentes; Colubroidea; Viperidae; Viperinae; Bitis.
OX NCBI_TaxID=8693;
RN [1]
RP PROTEIN SEQUENCE, FUNCTION, AND TOXIC DOSE.
RC TISSUE=Venom;
RX PubMed=7135414; DOI=10.1016/0041-0101(82)90120-9;
RA Viljoen C.C., Botes D.P., Kruger H.;
RT "Isolation and amino acid sequence of caudoxin, a presynaptic acting toxic
RT phospholipase A2 from the venom of the horned puff adder (Bitis
RT caudalis).";
RL Toxicon 20:715-737(1982).
RN [2]
RP CRYSTALLIZATION, AND SUBUNIT.
RX PubMed=1801329; DOI=10.1016/0041-0101(91)90009-g;
RA Scott D.L., Achari A., Christensen P.A., Viljoen C.C., Sigler P.B.;
RT "Crystallization and preliminary diffraction analysis of caudoxin and
RT notexin; two monomeric phospholipase A2 neurotoxins.";
RL Toxicon 29:1517-1521(1991).
RN [3]
RP FUNCTION AS PROTHROMBINASE COMPLEX INHIBITOR.
RX PubMed=10462445; DOI=10.1006/abbi.1999.1345;
RA Kerns R.T., Kini R.M., Stefansson S., Evans H.J.;
RT "Targeting of venom phospholipases: the strongly anticoagulant
RT phospholipase A(2) from Naja nigricollis venom binds to coagulation factor
RT Xa to inhibit the prothrombinase complex.";
RL Arch. Biochem. Biophys. 369:107-113(1999).
CC -!- FUNCTION: Snake venom phospholipase A2 (PLA2) that shows anticoagulant
CC activity and presynaptic neurotoxicity. Acts as an anticoagulant toxin
CC by inhibiting prothrombinase complex formation. Shows about 50% of the
CC prothrombinase complex inhibition compared to CM-IV of N.nigricollis
CC venom. Acts as a neurotoxin by inhibiting neuromuscular transmission by
CC blocking acetylcholine release from the nerve termini. PLA2 catalyzes
CC the calcium-dependent hydrolysis of the 2-acyl groups in 3-sn-
CC phosphoglycerides. {ECO:0000269|PubMed:10462445,
CC ECO:0000269|PubMed:7135414}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=a 1,2-diacyl-sn-glycero-3-phosphocholine + H2O = a 1-acyl-sn-
CC glycero-3-phosphocholine + a fatty acid + H(+); Xref=Rhea:RHEA:15801,
CC ChEBI:CHEBI:15377, ChEBI:CHEBI:15378, ChEBI:CHEBI:28868,
CC ChEBI:CHEBI:57643, ChEBI:CHEBI:58168; EC=3.1.1.4;
CC Evidence={ECO:0000255|PROSITE-ProRule:PRU10035, ECO:0000255|PROSITE-
CC ProRule:PRU10036};
CC -!- COFACTOR:
CC Name=Ca(2+); Xref=ChEBI:CHEBI:29108; Evidence={ECO:0000250};
CC Note=Binds 1 Ca(2+) ion. {ECO:0000250};
CC -!- SUBUNIT: Monomer. {ECO:0000269|PubMed:1801329}.
CC -!- SUBCELLULAR LOCATION: Secreted.
CC -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC -!- TOXIC DOSE: LD(50) is 0.18 mg/kg by intraperitoneal injection.
CC {ECO:0000269|PubMed:7135414}.
CC -!- SIMILARITY: Belongs to the phospholipase A2 family. Group II subfamily.
CC D49 sub-subfamily. {ECO:0000305}.
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DR PIR; A00762; PSBGAC.
DR AlphaFoldDB; P00622; -.
DR SMR; P00622; -.
DR GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR GO; GO:0005509; F:calcium ion binding; IEA:InterPro.
DR GO; GO:0004623; F:phospholipase A2 activity; IEA:UniProtKB-EC.
DR GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR GO; GO:0050482; P:arachidonic acid secretion; IEA:InterPro.
DR GO; GO:0016042; P:lipid catabolic process; IEA:UniProtKB-KW.
DR GO; GO:0006644; P:phospholipid metabolic process; IEA:InterPro.
DR CDD; cd00125; PLA2c; 1.
DR Gene3D; 1.20.90.10; -; 1.
DR InterPro; IPR001211; PLipase_A2.
DR InterPro; IPR033112; PLipase_A2_Asp_AS.
DR InterPro; IPR016090; PLipase_A2_dom.
DR InterPro; IPR036444; PLipase_A2_dom_sf.
DR InterPro; IPR033113; PLipase_A2_His_AS.
DR PANTHER; PTHR11716; PTHR11716; 1.
DR Pfam; PF00068; Phospholip_A2_1; 1.
DR PRINTS; PR00389; PHPHLIPASEA2.
DR SMART; SM00085; PA2c; 1.
DR SUPFAM; SSF48619; SSF48619; 1.
DR PROSITE; PS00119; PA2_ASP; 1.
DR PROSITE; PS00118; PA2_HIS; 1.
PE 1: Evidence at protein level;
KW Blood coagulation cascade inhibiting toxin; Calcium;
KW Direct protein sequencing; Disulfide bond; Hemostasis impairing toxin;
KW Hydrolase; Lipid degradation; Lipid metabolism; Metal-binding; Neurotoxin;
KW Presynaptic neurotoxin; Secreted; Toxin.
FT CHAIN 1..121
FT /note="Basic phospholipase A2 caudoxin"
FT /id="PRO_0000161614"
FT ACT_SITE 46
FT /evidence="ECO:0000250"
FT ACT_SITE 88
FT /evidence="ECO:0000250"
FT BINDING 26
FT /ligand="Ca(2+)"
FT /ligand_id="ChEBI:CHEBI:29108"
FT /evidence="ECO:0000250"
FT BINDING 28
FT /ligand="Ca(2+)"
FT /ligand_id="ChEBI:CHEBI:29108"
FT /evidence="ECO:0000250"
FT BINDING 30
FT /ligand="Ca(2+)"
FT /ligand_id="ChEBI:CHEBI:29108"
FT /evidence="ECO:0000250"
FT BINDING 47
FT /ligand="Ca(2+)"
FT /ligand_id="ChEBI:CHEBI:29108"
FT /evidence="ECO:0000250"
FT DISULFID 25..114
FT /evidence="ECO:0000250"
FT DISULFID 27..43
FT /evidence="ECO:0000250"
FT DISULFID 42..94
FT /evidence="ECO:0000250"
FT DISULFID 48..121
FT /evidence="ECO:0000250"
FT DISULFID 49..87
FT /evidence="ECO:0000250"
FT DISULFID 56..80
FT /evidence="ECO:0000250"
FT DISULFID 74..85
FT /evidence="ECO:0000250"
SQ SEQUENCE 121 AA; 13363 MW; DC0500A87839E504 CRC64;
NLIQFGNMIS AMTGKSSLAY ASYGCYCGWG GKGQPKDDTD RCCFVHDCCY GKADKCSPKM
ILYSYKFHNG NIVCGDKNAC KKKVCECDRV AAICFAASKH SYNKNLWRYP SSKCTGTAEK
C
