PA2B1_CROSS
ID PA2B1_CROSS Reviewed; 138 AA.
AC P62023; P07517; P23559;
DT 01-APR-1988, integrated into UniProtKB/Swiss-Prot.
DT 07-JUN-2004, sequence version 1.
DT 03-AUG-2022, entry version 75.
DE RecName: Full=Basic phospholipase A2 Mtx-b;
DE Short=svPLA2;
DE EC=3.1.1.4;
DE AltName: Full=Mojave toxin basic chain;
DE AltName: Full=Phosphatidylcholine 2-acylhydrolase;
DE AltName: Full=Phospholipase A2 CB1;
DE Flags: Precursor;
OS Crotalus scutulatus scutulatus (Mojave rattlesnake).
OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Toxicofera;
OC Serpentes; Colubroidea; Viperidae; Crotalinae; Crotalus.
OX NCBI_TaxID=8738;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC TISSUE=Liver;
RX PubMed=8112610; DOI=10.1016/0378-1119(94)90761-7;
RA John T.R., Smith L.A., Kaiser I.I.;
RT "Genomic sequences encoding the acidic and basic subunits of Mojave toxin:
RT unusually high sequence identity of non-coding regions.";
RL Gene 139:229-234(1994).
RN [2]
RP PROTEIN SEQUENCE OF 17-138.
RC TISSUE=Venom;
RX PubMed=2402763; DOI=10.1016/0041-0101(90)90255-6;
RA Aird S.D., Kruggel W.G., Kaiser I.I.;
RT "Amino acid sequence of the basic subunit of Mojave toxin from the venom of
RT the Mojave rattlesnake (Crotalus s. scutulatus).";
RL Toxicon 28:669-673(1990).
RN [3]
RP PROTEIN SEQUENCE OF 17-39, FUNCTION, SUBUNIT, AND MASS SPECTROMETRY.
RC TISSUE=Venom;
RX PubMed=15032748; DOI=10.1042/bj20040125;
RA Chen Y.-H., Wang Y.-M., Hseu M.-J., Tsai I.-H.;
RT "Molecular evolution and structure-function relationships of crotoxin-like
RT and asparagine-6-containing phospholipases A2 in pit viper venoms.";
RL Biochem. J. 381:25-34(2004).
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:15032748}.
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 of an acidic subunit and a basic chain. The acidic
CC subunit is non-toxic, without enzymatic activity and comprises 3
CC peptides that are cross-linked by 7 disulfide bridges. The basic
CC subunit is toxic, has phospholipase A2 activity and is composed of a
CC single chain. {ECO:0000269|PubMed:15032748}.
CC -!- SUBCELLULAR LOCATION: Secreted.
CC -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC -!- MASS SPECTROMETRY: Mass=14183; Method=Electrospray;
CC Evidence={ECO:0000269|PubMed:15032748};
CC -!- SIMILARITY: Belongs to the phospholipase A2 family. Group II subfamily.
CC D49 sub-subfamily. {ECO:0000305}.
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DR EMBL; U01027; AAC59674.1; -; Genomic_DNA.
DR PIR; I51381; I51381.
DR AlphaFoldDB; P62023; -.
DR SMR; P62023; -.
DR ABCD; P62023; 1 sequenced antibody.
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..16
FT /evidence="ECO:0000269|PubMed:15032748,
FT ECO:0000269|PubMed:2402763"
FT CHAIN 17..138
FT /note="Basic phospholipase A2 Mtx-b"
FT /id="PRO_0000022860"
FT ACT_SITE 63
FT /evidence="ECO:0000250|UniProtKB:P62022"
FT ACT_SITE 105
FT /evidence="ECO:0000250|UniProtKB:P62022"
FT BINDING 43
FT /ligand="Ca(2+)"
FT /ligand_id="ChEBI:CHEBI:29108"
FT /evidence="ECO:0000250|UniProtKB:P62022"
FT BINDING 45
FT /ligand="Ca(2+)"
FT /ligand_id="ChEBI:CHEBI:29108"
FT /evidence="ECO:0000250|UniProtKB:P62022"
FT BINDING 47
FT /ligand="Ca(2+)"
FT /ligand_id="ChEBI:CHEBI:29108"
FT /evidence="ECO:0000250|UniProtKB:P62022"
FT BINDING 64
FT /ligand="Ca(2+)"
FT /ligand_id="ChEBI:CHEBI:29108"
FT /evidence="ECO:0000250|UniProtKB:P62022"
FT DISULFID 42..131
FT /evidence="ECO:0000250|UniProtKB:P62022"
FT DISULFID 44..60
FT /evidence="ECO:0000250|UniProtKB:P62022"
FT DISULFID 59..111
FT /evidence="ECO:0000250|UniProtKB:P62022"
FT DISULFID 65..138
FT /evidence="ECO:0000250|UniProtKB:P62022"
FT DISULFID 66..104
FT /evidence="ECO:0000250|UniProtKB:P62022"
FT DISULFID 73..97
FT /evidence="ECO:0000250|UniProtKB:P62022"
FT DISULFID 91..102
FT /evidence="ECO:0000250|UniProtKB:P62022"
SQ SEQUENCE 138 AA; 15907 MW; 84A118931DFFE2E3 CRC64;
MRALWIVAVL LVGVEGHLLQ FNKMIKFETR KNAIPFYAFY GCYCGWGGRG RPKDATDRCC
FVHDCCYGKL AKCNTKWDIY PYSLKSGYIT CGKGTWCEEQ ICECDRVAAE CLRRSLSTYK
YGYMFYPDSR CRGPSETC
