PA2B1_BUNFL
ID PA2B1_BUNFL Reviewed; 146 AA.
AC Q7T1R0;
DT 09-JAN-2007, integrated into UniProtKB/Swiss-Prot.
DT 01-OCT-2003, sequence version 1.
DT 03-AUG-2022, entry version 73.
DE RecName: Full=Basic phospholipase A2 beta-bungarotoxin A1 chain;
DE Short=Beta-BuTX A1 chain;
DE Short=svPLA2;
DE EC=3.1.1.4;
DE AltName: Full=Phosphatidylcholine 2-acylhydrolase;
DE Flags: Precursor;
OS Bungarus flaviceps flaviceps (Red-headed krait).
OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Toxicofera;
OC Serpentes; Colubroidea; Elapidae; Bungarinae; Bungarus.
OX NCBI_TaxID=8615;
RN [1]
RP NUCLEOTIDE SEQUENCE [MRNA], PROTEIN SEQUENCE OF 28-50; 59-70; 93-97 AND
RP 101-143, IDENTIFICATION BY MASS SPECTROMETRY, AND SUBUNIT.
RC TISSUE=Venom gland;
RX PubMed=16458338; DOI=10.1016/j.toxicon.2005.12.004;
RA Yanoshita R., Ogawa Y., Murayama N., Omori-Satoh T., Saguchi K.,
RA Higuchi S., Khow O., Chanhome L., Samejima Y., Sitprija V.;
RT "Molecular cloning of the major lethal toxins from two kraits (Bungarus
RT flaviceps and Bungarus candidus).";
RL Toxicon 47:416-424(2006).
RN [2]
RP FUNCTION, AND SUBUNIT.
RC TISSUE=Venom;
RX PubMed=11738240; DOI=10.1016/s0041-0101(01)00235-5;
RA Khow O., Chanhome L., Omori-Satoh T., Sitprija V.;
RT "Isolation of the major lethal toxin in the venom of Bungarus flaviceps.";
RL Toxicon 40:463-469(2002).
CC -!- FUNCTION: Snake venom phospholipase A2 (PLA2) that inhibits
CC neuromuscular transmission by blocking acetylcholine release from the
CC nerve termini. PLA2 catalyzes the calcium-dependent hydrolysis of the
CC 2-acyl groups in 3-sn-phosphoglycerides. {ECO:0000269|PubMed:11738240}.
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: Heterodimer with beta-bungarotoxin B chain; disulfide-linked.
CC The A chain has phospholipase A2 activity and the B chain shows
CC homology with the basic protease inhibitors.
CC {ECO:0000269|PubMed:11738240, ECO:0000269|PubMed:16458338}.
CC -!- SUBCELLULAR LOCATION: Secreted.
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}.
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DR EMBL; AB112357; BAC77653.1; -; mRNA.
DR AlphaFoldDB; Q7T1R0; -.
DR SMR; Q7T1R0; -.
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; Direct protein sequencing; Disulfide bond; Hydrolase;
KW Lipid degradation; Lipid metabolism; Metal-binding; Neurotoxin;
KW Presynaptic neurotoxin; Secreted; Signal; Toxin.
FT SIGNAL 1..19
FT /evidence="ECO:0000255"
FT PROPEP 20..27
FT /evidence="ECO:0000269|PubMed:16458338"
FT /id="PRO_0000271455"
FT CHAIN 28..146
FT /note="Basic phospholipase A2 beta-bungarotoxin A1 chain"
FT /id="PRO_5000050833"
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 42
FT /note="Interchain (with a B chain)"
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 87..112
FT /evidence="ECO:0000250"
FT DISULFID 105..117
FT /evidence="ECO:0000250"
SQ SEQUENCE 146 AA; 16394 MW; 64C0C4D991908662 CRC64;
MNPAHLLVLP AVCVSFLGAS IIPPQSLNLI QFKDMIRCTI PCERTWGEYA DYGCYCGKGG
SGRPVDALDR CCYVHDNCYG EAQKRNCNPY MKSYSFKCAK RTLFCYDAPG SCARFVCDCD
RTAALCFGDS EYIGRHKNID TKRHCQ
