PA2H_CROAT
ID PA2H_CROAT Reviewed; 137 AA.
AC Q8UVZ7;
DT 06-DEC-2002, integrated into UniProtKB/Swiss-Prot.
DT 01-MAR-2002, sequence version 1.
DT 25-MAY-2022, entry version 84.
DE RecName: Full=Basic phospholipase A2 homolog Cax-K49 {ECO:0000303|PubMed:11594738};
DE Short=svPLA2 homolog;
DE Flags: Precursor;
OS Crotalus atrox (Western diamondback rattlesnake).
OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Toxicofera;
OC Serpentes; Colubroidea; Viperidae; Crotalinae; Crotalus.
OX NCBI_TaxID=8730;
RN [1]
RP NUCLEOTIDE SEQUENCE [MRNA], PROTEIN SEQUENCE OF 17-45, FUNCTION, MASS
RP SPECTROMETRY, AND SUBCELLULAR LOCATION.
RC TISSUE=Venom, and Venom gland;
RX PubMed=11594738; DOI=10.1006/abbi.2001.2524;
RA Tsai I.-H., Chen Y.-H., Wang Y.-M., Tu M.-C., Tu A.T.;
RT "Purification, sequencing, and phylogenetic analyses of novel Lys-49
RT phospholipases A(2) from the venoms of rattlesnakes and other pit vipers.";
RL Arch. Biochem. Biophys. 394:236-244(2001).
RN [2]
RP PROTEIN SEQUENCE OF 17-49; 54-64; 77-85 AND 88-99, IDENTIFICATION BY MASS
RP SPECTROMETRY, AND SUBCELLULAR LOCATION.
RC TISSUE=Venom;
RX PubMed=19371136; DOI=10.1021/pr900249q;
RA Calvete J.J., Fasoli E., Sanz L., Boschetti E., Righetti P.G.;
RT "Exploring the venom proteome of the western diamondback rattlesnake,
RT Crotalus atrox, via snake venomics and combinatorial peptide ligand library
RT approaches.";
RL J. Proteome Res. 8:3055-3067(2009).
CC -!- FUNCTION: Snake venom phospholipase A2 homolog that lacks enzymatic
CC activity (PubMed:11594738). Displays edema-inducing activities and may
CC be myotoxic (PubMed:11594738). A model of myotoxic mechanism has been
CC proposed: an apo Lys49-PLA2 is activated by the entrance of a
CC hydrophobic molecule (e.g. fatty acid) at the hydrophobic channel of
CC the protein leading to a reorientation of a monomer (By similarity).
CC This reorientation causes a transition between 'inactive' to 'active'
CC states, causing alignment of C-terminal and membrane-docking sites
CC (MDoS) side-by-side and putting the membrane-disruption sites (MDiS) in
CC the same plane, exposed to solvent and in a symmetric position for both
CC monomers (By similarity). The MDoS region stabilizes the toxin on
CC membrane by the interaction of charged residues with phospholipid head
CC groups (By similarity). Subsequently, the MDiS region destabilizes the
CC membrane with penetration of hydrophobic residues (By similarity). This
CC insertion causes a disorganization of the membrane, allowing an
CC uncontrolled influx of ions (i.e. calcium and sodium), and eventually
CC triggering irreversible intracellular alterations and cell death (By
CC similarity). {ECO:0000250|UniProtKB:I6L8L6,
CC ECO:0000269|PubMed:11594738}.
CC -!- SUBUNIT: Homodimer; non-covalently linked.
CC {ECO:0000250|UniProtKB:I6L8L6}.
CC -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:11594738,
CC ECO:0000269|PubMed:19371136}.
CC -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC {ECO:0000305|PubMed:11594738, ECO:0000305|PubMed:19371136}.
CC -!- MASS SPECTROMETRY: Mass=13779; Method=Electrospray;
CC Evidence={ECO:0000269|PubMed:11594738};
CC -!- SIMILARITY: Belongs to the phospholipase A2 family. Group II subfamily.
CC K49 sub-subfamily. {ECO:0000305}.
CC -!- CAUTION: Does not bind calcium as one of the calcium-binding sites is
CC lost (Asp->Lys in position 64, which corresponds to 'Lys-49' in the
CC current nomenclature). {ECO:0000305}.
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DR EMBL; AF269130; AAL36973.1; -; mRNA.
DR AlphaFoldDB; Q8UVZ7; -.
DR SMR; Q8UVZ7; -.
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:InterPro.
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:InterPro.
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 Direct protein sequencing; Disulfide bond; Myotoxin; Secreted; Signal;
KW Toxin.
FT SIGNAL 1..16
FT /evidence="ECO:0000269|PubMed:11594738,
FT ECO:0000269|PubMed:19371136"
FT CHAIN 17..137
FT /note="Basic phospholipase A2 homolog Cax-K49"
FT /id="PRO_0000022852"
FT REGION 121..133
FT /note="Important for membrane-damaging activities in
FT eukaryotes and bacteria; heparin-binding"
FT /evidence="ECO:0000250|UniProtKB:P24605"
FT SITE 121
FT /note="Important residue of the cationic membrane-docking
FT site (MDoS)"
FT /evidence="ECO:0000250|UniProtKB:I6L8L6"
FT SITE 124
FT /note="Important residue of the cationic membrane-docking
FT site (MDoS)"
FT /evidence="ECO:0000250|UniProtKB:I6L8L6"
FT SITE 128
FT /note="Cationic membrane-docking site (MDoS)"
FT /evidence="ECO:0000250|UniProtKB:I6L8L6"
FT SITE 130
FT /note="Hydrophobic membrane-disruption site (MDiS)"
FT /evidence="ECO:0000250|UniProtKB:I6L8L6"
FT SITE 133
FT /note="Cationic membrane-docking site (MDoS)"
FT /evidence="ECO:0000250|UniProtKB:I6L8L6"
FT DISULFID 42..131
FT /evidence="ECO:0000250|UniProtKB:Q90249"
FT DISULFID 44..60
FT /evidence="ECO:0000250|UniProtKB:Q90249"
FT DISULFID 59..111
FT /evidence="ECO:0000250|UniProtKB:Q90249"
FT DISULFID 65..137
FT /evidence="ECO:0000250|UniProtKB:Q90249"
FT DISULFID 66..104
FT /evidence="ECO:0000250|UniProtKB:Q90249"
FT DISULFID 73..97
FT /evidence="ECO:0000250|UniProtKB:Q90249"
FT DISULFID 91..102
FT /evidence="ECO:0000250|UniProtKB:Q90249"
SQ SEQUENCE 137 AA; 15597 MW; 63E5F80D0565AEE6 CRC64;
MRTFWIVAML LVGVEGSLVE LGKMILQETG KNPITSYGIY GCNCGVGSRH KPKDGTDRCC
FVHKCCYKKL TDCDPKMDGY TYSFKDKTII CDVNNPCLKE MCECDKAVAI CLRENLDTYN
KKYKIYPKFL CKKPDTC
