PA2AB_DABSI
ID PA2AB_DABSI Reviewed; 130 AA.
AC Q7T3T5;
DT 03-OCT-2012, integrated into UniProtKB/Swiss-Prot.
DT 01-OCT-2003, sequence version 1.
DT 03-AUG-2022, entry version 81.
DE RecName: Full=Acidic phospholipase A2 daboiatoxin B chain;
DE Short=DbTx-B;
DE Short=svPLA2;
DE EC=3.1.1.4;
DE AltName: Full=Acidic phospholipase A2-II;
DE AltName: Full=Phosphatidylcholine 2-acylhydrolase;
DE Flags: Precursor; Fragment;
OS Daboia siamensis (Eastern Russel's viper) (Daboia russelii siamensis).
OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Toxicofera;
OC Serpentes; Colubroidea; Viperidae; Viperinae; Daboia.
OX NCBI_TaxID=343250;
RN [1]
RP NUCLEOTIDE SEQUENCE [MRNA].
RA Jia Y.-H., Jin Y., Chen R.-Q., Li D.-S., Wang W.-Y., Xiong Y.-L.;
RT "Biochemical and pharmacological properties of three phospholipases from
RT Vipera russelli siamensis.";
RL Submitted (APR-2003) to the EMBL/GenBank/DDBJ databases.
RN [2]
RP FUNCTION.
RX PubMed=7778130; DOI=10.1016/0041-0101(94)00133-s;
RA Thwin M.M., Gopalakrishnakone P., Yuen R., Tan C.H.;
RT "A major lethal factor of the venom of Burmese Russell's viper (Daboia
RT russelli siamensis): isolation, N-terminal sequencing and biological
RT activities of daboiatoxin.";
RL Toxicon 33:63-76(1995).
RN [3]
RP FUNCTION.
RX PubMed=8711753; DOI=10.1016/0041-0101(95)00134-4;
RA Thwin M.M., Gopalakrishnakone P., Yuen R., Tan C.H.;
RT "Synaptosomal binding of 125I-labelled daboiatoxin, a new PLA2 neurotoxin
RT from the venom of Daboia russelli siamensis.";
RL Toxicon 34:183-199(1996).
RN [4]
RP X-RAY CRYSTALLOGRAPHY (2.60 ANGSTROMS) OF 9-130, DISULFIDE BOND, SUBUNIT,
RP AND TOXIC DOSE.
RC TISSUE=Venom;
RX PubMed=17505111; DOI=10.1107/s0907444907016204;
RA Gopalan G., Thwin M.M., Gopalakrishnakone P., Swaminathan K.;
RT "Structural and pharmacological comparison of daboiatoxin from Daboia
RT russelli siamensis with viperotoxin F and vipoxin from other vipers.";
RL Acta Crystallogr. D 63:722-729(2007).
CC -!- FUNCTION: Monomer: Snake venom phospholipase A2 (PLA2) that shows a
CC high PLA2 activity (2110 umol/min/mg).
CC -!- FUNCTION: Heterodimer (A and B chains): snake venom phospholipase A2
CC that shows a moderate PLA2 activity (1377 umol/min/mg). Acts as a
CC presynaptic neurotoxin. In vivo, induces edema and produces neurotoxic
CC symptoms in mice. It exhibits indirect hemolysis and a strong
CC myonecrotic activity and is cytotoxic. PLA2 catalyzes the calcium-
CC dependent hydrolysis of the 2-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};
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 protein having phospholipase A2
CC activity (B chain) and an A chain which weakly inhibits the B chain
CC enzymatic activity but potentiates its lethal potency.
CC {ECO:0000269|PubMed:17505111}.
CC -!- SUBCELLULAR LOCATION: Secreted.
CC -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC -!- TOXIC DOSE: Monomer: LD(50) of DbTx-B alone is estimated to be 0.5 ug/g
CC by intraperitoneal injection into mice. {ECO:0000269|PubMed:17505111}.
CC -!- TOXIC DOSE: Heterodimer (A and B chains): LD(50) is estimated to be
CC about 0.1 ug/g by intraperitoneal injection into mice.
CC {ECO:0000269|PubMed:17505111}.
CC -!- MISCELLANEOUS: Does not provoke hemorrhage.
CC {ECO:0000305|PubMed:7778130}.
CC -!- SIMILARITY: Belongs to the phospholipase A2 family. Group II subfamily.
CC D49 sub-subfamily. {ECO:0000305}.
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DR EMBL; AY286006; AAP37177.1; -; mRNA.
DR PDB; 2H4C; X-ray; 2.60 A; B/D/F/H=9-130.
DR PDBsum; 2H4C; -.
DR AlphaFoldDB; Q7T3T5; -.
DR SMR; Q7T3T5; -.
DR EvolutionaryTrace; Q7T3T5; -.
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:0006954; P:inflammatory response; IEA:UniProtKB-KW.
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 3D-structure; Calcium; Disulfide bond; Hydrolase; Inflammatory response;
KW Lipid degradation; Lipid metabolism; Metal-binding; Myotoxin; Neurotoxin;
KW Presynaptic neurotoxin; Secreted; Signal; Toxin.
FT SIGNAL <1..8
FT CHAIN 9..130
FT /note="Acidic phospholipase A2 daboiatoxin B chain"
FT /id="PRO_0000419223"
FT ACT_SITE 55
FT /evidence="ECO:0000250"
FT ACT_SITE 97
FT /evidence="ECO:0000250"
FT BINDING 35
FT /ligand="Ca(2+)"
FT /ligand_id="ChEBI:CHEBI:29108"
FT /evidence="ECO:0000250"
FT BINDING 37
FT /ligand="Ca(2+)"
FT /ligand_id="ChEBI:CHEBI:29108"
FT /evidence="ECO:0000250"
FT BINDING 39
FT /ligand="Ca(2+)"
FT /ligand_id="ChEBI:CHEBI:29108"
FT /evidence="ECO:0000250"
FT BINDING 56
FT /ligand="Ca(2+)"
FT /ligand_id="ChEBI:CHEBI:29108"
FT /evidence="ECO:0000250"
FT DISULFID 34..123
FT /evidence="ECO:0000269|PubMed:17505111"
FT DISULFID 36..52
FT /evidence="ECO:0000269|PubMed:17505111"
FT DISULFID 51..103
FT /evidence="ECO:0000269|PubMed:17505111"
FT DISULFID 57..130
FT /evidence="ECO:0000269|PubMed:17505111"
FT DISULFID 58..96
FT /evidence="ECO:0000269|PubMed:17505111"
FT DISULFID 65..89
FT /evidence="ECO:0000269|PubMed:17505111"
FT DISULFID 83..94
FT /evidence="ECO:0000269|PubMed:17505111"
FT NON_TER 1
FT HELIX 10..20
FT /evidence="ECO:0007829|PDB:2H4C"
FT TURN 23..26
FT /evidence="ECO:0007829|PDB:2H4C"
FT HELIX 27..29
FT /evidence="ECO:0007829|PDB:2H4C"
FT TURN 33..35
FT /evidence="ECO:0007829|PDB:2H4C"
FT STRAND 36..38
FT /evidence="ECO:0007829|PDB:2H4C"
FT HELIX 47..59
FT /evidence="ECO:0007829|PDB:2H4C"
FT STRAND 67..69
FT /evidence="ECO:0007829|PDB:2H4C"
FT STRAND 75..77
FT /evidence="ECO:0007829|PDB:2H4C"
FT STRAND 80..82
FT /evidence="ECO:0007829|PDB:2H4C"
FT HELIX 88..106
FT /evidence="ECO:0007829|PDB:2H4C"
FT STRAND 108..110
FT /evidence="ECO:0007829|PDB:2H4C"
FT TURN 120..122
FT /evidence="ECO:0007829|PDB:2H4C"
SQ SEQUENCE 130 AA; 14828 MW; 3C8DB0AAF3C47689 CRC64;
MCLIGVEGNL FQFARLIDAK QEAFSFFKYI SYGCYCGWGG QGTPKDATDR CCFVHDCCYA
RVKGCNPKLV EYSYSYRTGK IVCGGDDPCL RAVCECDRVA AICFRENMNT YDKKYMLYSI
FDCKEESDQC
