ID   PA2TA_OXYSC             Reviewed;         119 AA.
AC   P00614;
DT   21-JUL-1986, integrated into UniProtKB/Swiss-Prot.
DT   21-JUL-1986, sequence version 1.
DT   02-SEP-2026, entry version 128.
DE   RecName: Full=Basic phospholipase A2 taipoxin alpha chain;
DE            Short=svPLA2;
DE            EC=3.1.1.4;
DE   AltName: Full=Phosphatidylcholine 2-acylhydrolase;
OS   Oxyuranus scutellatus scutellatus (Australian taipan) (Coastal taipan).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC   Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Toxicofera;
OC   Serpentes; Colubroidea; Elapidae; Hydrophiinae; Oxyuranus.
OX   NCBI_TaxID=8667;
RN   [1]
RP   PROTEIN SEQUENCE.
RC   TISSUE=Venom;
RX   PubMed=7049694; DOI=10.1111/j.1432-1033.1982.tb06612.x;
RA   Lind P., Eaker D.;
RT   "Amino-acid sequence of the alpha-subunit of taipoxin, an extremely potent
RT   presynaptic neurotoxin from the Australian snake taipan (Oxyuranus s.
RT   scutellatus).";
RL   Eur. J. Biochem. 124:441-447(1982).
RN   [2]
RP   PROTEIN SEQUENCE OF 1-4, FUNCTION, ENZYMATIC ACTIVITY, AND MASS
RP   SPECTROMETRY.
RC   TISSUE=Venom;
RX   PubMed=22776098; DOI=10.1111/j.1742-4658.2012.08691.x;
RA   Cendron L., Micetic I., Polverino de Laureto P., Paoli M.;
RT   "Structural analysis of trimeric phospholipase A2 neurotoxin from the
RT   Australian taipan snake venom.";
RL   FEBS J. 279:3121-3135(2012).
RN   [3]
RP   FUNCTION, SUBUNIT, AND TOXIC DOSE.
RC   TISSUE=Venom;
RX   PubMed=976268; DOI=10.1111/j.1432-1033.1976.tb10833.x;
RA   Fohlman J., Eaker D., Karlsoon E., Thesleff S.;
RT   "Taipoxin, an extremely potent presynaptic neurotoxin from the venom of the
RT   australian snake taipan (Oxyuranus s. scutellatus). Isolation,
RT   characterization, quaternary structure and pharmacological properties.";
RL   Eur. J. Biochem. 68:457-469(1976).
RN   [4]
RP   FUNCTION AS RCN2 BINDING PROTEIN.
RX   PubMed=7722520; DOI=10.1046/j.1471-4159.1995.64052339.x;
RA   Dodds D., Schlimgen A.K., Lu S.Y., Perin M.S.;
RT   "Novel reticular calcium binding protein is purified on taipoxin columns.";
RL   J. Neurochem. 64:2339-2344(1995).
RN   [5]
RP   FUNCTION AS PENTRAXIN BINDING PROTEIN.
RX   PubMed=10748068; DOI=10.1074/jbc.m002254200;
RA   Kirkpatrick L.L., Matzuk M.M., Dodds D.C., Perin M.S.;
RT   "Biochemical interactions of the neuronal pentraxins. Neuronal pentraxin
RT   (NP) receptor binds to taipoxin and taipoxin-associated calcium-binding
RT   protein 49 via NP1 and NP2.";
RL   J. Biol. Chem. 275:17786-17792(2000).
CC   -!- FUNCTION: Heterotrimer: Snake venom phospholipase A2 (PLA2)
CC       heterotrimer that acts as a potent presynaptic neurotoxin by blocking
CC       synaptic transmission and synaptic vesicle recycling. May act by
CC       binding in a calcium-dependent fashion to neurotonal pentraxin-1
CC       (NPTX1) and neurotonal pentraxin-2 (NPTX2), but not to neuronal
CC       pentraxin receptor (NPTXR). Also binds to taipoxin-associated calcium
CC       binding protein 49 (RCN2), a protein localized in the lumen of
CC       endoplasmic reticulum.
CC   -!- FUNCTION: Monomer (alpha chain): Snake venom phospholipase A2 (PLA2)
CC       alpha chain that possesses the same high enzymatic activity as the
CC       heterotrimer. PLA2 catalyzes the calcium-dependent hydrolysis of the 2-
CC       acyl groups in 3-sn-phosphoglycerides.
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, ECO:0000269|PubMed:22776098};
CC   -!- COFACTOR:
CC       Name=Ca(2+); Xref=ChEBI:CHEBI:29108; Evidence={ECO:0000250};
CC       Note=Binds 1 Ca(2+) ion. {ECO:0000250};
CC   -!- SUBUNIT: Heterotrimer of alpha, beta, and gamma chains; non-covalently
CC       linked. {ECO:0000269|PubMed:976268}.
CC   -!- SUBCELLULAR LOCATION: Secreted.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC   -!- MASS SPECTROMETRY: Mass=13987.9; Mass_error=0.8; Method=Electrospray;
CC       Evidence={ECO:0000269|PubMed:22776098};
CC   -!- TOXIC DOSE: Monomer (alpha chain): LD(50) is 0.3 mg/kg by intravenous
CC       injection into mice. {ECO:0000269|PubMed:976268}.
CC   -!- TOXIC DOSE: Heterotrimer: LD(50) is 2 ug/kg by intravenous injection
CC       into mice. {ECO:0000269|PubMed:976268}.
CC   -!- SIMILARITY: Belongs to the phospholipase A2 family. Group I subfamily.
CC       D49 sub-subfamily. {ECO:0000305}.
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DR   PIR; A00754; PSOXA.
DR   AlphaFoldDB; P00614; -.
DR   SMR; P00614; -.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0004623; F:A2-type glycerophospholipase activity; IEA:UniProtKB-EC.
DR   GO; GO:0005509; F:calcium ion binding; IEA:InterPro.
DR   GO; GO:0005543; F:phospholipid binding; IEA:TreeGrafter.
DR   GO; GO:0050482; P:arachidonate secretion; IEA:InterPro.
DR   GO; GO:0016042; P:lipid catabolic process; IEA:InterPro.
DR   GO; GO:0006644; P:phospholipid metabolic process; IEA:InterPro.
DR   CDD; cd00125; PLA2c; 1.
DR   FunFam; 1.20.90.10:FF:000007; Acidic phospholipase A2; 1.
DR   Gene3D; 1.20.90.10; Phospholipase A2 domain; 1.
DR   InterPro; IPR001211; PLA2.
DR   InterPro; IPR016090; PLA2-like_dom.
DR   InterPro; IPR033112; PLA2_Asp_AS.
DR   InterPro; IPR033113; PLA2_histidine.
DR   InterPro; IPR036444; PLipase_A2_dom_sf.
DR   PANTHER; PTHR11716:SF51; PHOSPHOLIPASE A2; 1.
DR   PANTHER; PTHR11716; PHOSPHOLIPASE A2 FAMILY MEMBER; 1.
DR   Pfam; PF00068; Phospholip_A2_1; 1.
DR   PRINTS; PR00389; PHPHLIPASEA2.
DR   SMART; SM00085; PA2c; 1.
DR   SUPFAM; SSF48619; Phospholipase A2, PLA2; 1.
DR   PROSITE; PS00119; PA2_ASP; 1.
DR   PROSITE; PS00118; PA2_HIS; 1.
PE   1: Evidence at protein level;
KW   Calcium; Direct protein sequencing; Disulfide bond; Hydrolase;
KW   Lipid degradation; Lipid metabolism; Metal-binding; Neurotoxin;
KW   Presynaptic neurotoxin; Secreted; Toxin.
FT   CHAIN           1..119
FT                   /note="Basic phospholipase A2 taipoxin alpha chain"
FT                   /id="PRO_0000161678"
FT   ACT_SITE        48
FT                   /evidence="ECO:0000250"
FT   ACT_SITE        93
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         32
FT                   /ligand="Ca(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29108"
FT                   /evidence="ECO:0000250"
FT   BINDING         49
FT                   /ligand="Ca(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29108"
FT                   /evidence="ECO:0000250"
FT   DISULFID        11..72
FT                   /evidence="ECO:0000250"
FT   DISULFID        27..118
FT                   /evidence="ECO:0000250"
FT   DISULFID        29..45
FT                   /evidence="ECO:0000250"
FT   DISULFID        44..99
FT                   /evidence="ECO:0000250"
FT   DISULFID        51..92
FT                   /evidence="ECO:0000250"
FT   DISULFID        61..85
FT                   /evidence="ECO:0000250"
FT   DISULFID        79..90
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   119 AA;  13829 MW;  7FAFD5DD61105C03 CRC64;
     NLLQFGFMIR CANRRSRPVW HYMDYGCYCG KGGSGTPVDD LDRCCQVHDE CYGEAVRRFG
     CAPYWTLYSW KCYGKAPTCN TKTRCQRFVC RCDAKAAECF ARSPYQNSNW NINTKARCR
//