PA2PA_OXYMI
ID PA2PA_OXYMI Reviewed; 146 AA.
AC Q45Z42;
DT 09-JAN-2013, integrated into UniProtKB/Swiss-Prot.
DT 13-SEP-2005, sequence version 1.
DT 03-AUG-2022, entry version 75.
DE RecName: Full=Basic phospholipase A2 paradoxin-like alpha chain;
DE Short=svPLA2;
DE EC=3.1.1.4;
DE AltName: Full=PLA-4;
DE AltName: Full=Phosphatidylcholine 2-acylhydrolase;
DE Flags: Precursor;
OS Oxyuranus microlepidotus (Inland taipan) (Diemenia microlepidota).
OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Toxicofera;
OC Serpentes; Colubroidea; Elapidae; Acanthophiinae; Oxyuranus.
OX NCBI_TaxID=111177;
RN [1]
RP NUCLEOTIDE SEQUENCE [MRNA].
RC TISSUE=Venom gland;
RX PubMed=16261251; DOI=10.1007/s00018-005-5384-9;
RA St Pierre L., Woods R., Earl S.T.H., Masci P.P., Lavin M.F.;
RT "Identification and analysis of venom gland-specific genes from the coastal
RT taipan (Oxyuranus scutellatus) and related species.";
RL Cell. Mol. Life Sci. 62:2679-2693(2005).
RN [2]
RP FUNCTION, AND SUBUNIT.
RX PubMed=17313963; DOI=10.1016/j.neuropharm.2007.01.002;
RA Hodgson W.C., Dal Belo C.A., Rowan E.G.;
RT "The neuromuscular activity of paradoxin: a presynaptic neurotoxin from the
RT venom of the inland taipan (Oxyuranus microlepidotus).";
RL Neuropharmacology 52:1229-1236(2007).
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 (PubMed:17313963).
CC May act by binding in a calcium-dependent fashion to neurotonal
CC pentraxin-1 (NPTX1) and neurotonal pentraxin-2 (NPTX2), but not to
CC neuronal pentraxin receptor (NPTXR). Also binds to taipoxin-associated
CC calcium binding protein 49 (RCN2), a protein localized in the lumen of
CC endoplasmic reticulum (By similarity). {ECO:0000250,
CC ECO:0000269|PubMed:17313963}.
CC -!- FUNCTION: Monomer (alpha chain): Snake venom phospholipase A2 (PLA2)
CC alpha chain that possesses the same high enzymatic activity than the
CC heterotrimer. PLA2 catalyzes the calcium-dependent hydrolysis of the 2-
CC acyl groups in 3-sn-phosphoglycerides (By similarity). {ECO:0000250}.
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: Heterotrimer of alpha, beta, and gamma chains; non-covalently
CC linked. {ECO:0000250}.
CC -!- SUBCELLULAR LOCATION: Secreted {ECO:0000250}.
CC -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC -!- SIMILARITY: Belongs to the phospholipase A2 family. Group I subfamily.
CC D49 sub-subfamily. {ECO:0000305}.
CC -!- CAUTION: The assignment of paradoxin function to this sequence has been
CC made based on sequence similarity to taipoxin and cannitoxin. The gamma
CC chain has not yet been sequenced. {ECO:0000305}.
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DR EMBL; DQ085824; AAZ22642.1; -; mRNA.
DR AlphaFoldDB; Q45Z42; -.
DR SMR; Q45Z42; -.
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 Calcium; Disulfide bond; Hydrolase; Lipid degradation; Lipid metabolism;
KW Metal-binding; Neurotoxin; Presynaptic neurotoxin; Secreted; Signal; Toxin.
FT SIGNAL 1..27
FT /evidence="ECO:0000255"
FT CHAIN 28..146
FT /note="Basic phospholipase A2 paradoxin-like alpha chain"
FT /id="PRO_5000140349"
FT ACT_SITE 75
FT /evidence="ECO:0000250"
FT ACT_SITE 120
FT /evidence="ECO:0000250"
FT BINDING 55
FT /ligand="Ca(2+)"
FT /ligand_id="ChEBI:CHEBI:29108"
FT /evidence="ECO:0000250"
FT BINDING 57
FT /ligand="Ca(2+)"
FT /ligand_id="ChEBI:CHEBI:29108"
FT /evidence="ECO:0000250"
FT BINDING 59
FT /ligand="Ca(2+)"
FT /ligand_id="ChEBI:CHEBI:29108"
FT /evidence="ECO:0000250"
FT BINDING 76
FT /ligand="Ca(2+)"
FT /ligand_id="ChEBI:CHEBI:29108"
FT /evidence="ECO:0000250"
FT DISULFID 38..99
FT /evidence="ECO:0000250"
FT DISULFID 54..145
FT /evidence="ECO:0000250"
FT DISULFID 56..72
FT /evidence="ECO:0000250"
FT DISULFID 71..126
FT /evidence="ECO:0000250"
FT DISULFID 78..119
FT /evidence="ECO:0000250"
FT DISULFID 88..112
FT /evidence="ECO:0000250"
FT DISULFID 106..117
FT /evidence="ECO:0000250"
SQ SEQUENCE 146 AA; 16362 MW; 3AD5CEF1C76D4A98 CRC64;
MHPAHLLVLL AVCVSLLGAS DIPPLPLNLA QFGFMIKCAN HRSRPVSHYM DYGCYCGKGG
SGTPVDELDR CCQVHDECYG EAEKRFKCVP YMTLYSWKCY GTAPSCNTKT DCQRFVCNCD
AKAAECFARS PYQNKNWNIN TKARCK
