A1KA5_LOXSA
ID A1KA5_LOXSA Reviewed; 270 AA.
AC C0JAY9;
DT 23-MAR-2010, integrated into UniProtKB/Swiss-Prot.
DT 05-MAY-2009, sequence version 1.
DT 03-AUG-2022, entry version 37.
DE RecName: Full=Dermonecrotic toxin LsaSicTox-alphaIB1av {ECO:0000303|PubMed:19042943};
DE EC=4.6.1.- {ECO:0000250|UniProtKB:Q4ZFU2};
DE AltName: Full=Phospholipase D;
DE Short=PLD;
DE AltName: Full=Sphingomyelin phosphodiesterase D;
DE Short=SMD;
DE Short=SMase D;
DE Short=Sphingomyelinase D;
DE Flags: Fragment;
OS Loxosceles sabina (Tucson recluse spider).
OC Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida; Araneae;
OC Araneomorphae; Haplogynae; Scytodoidea; Sicariidae; Loxosceles.
OX NCBI_TaxID=571529;
RN [1]
RP NUCLEOTIDE SEQUENCE [MRNA], AND NOMENCLATURE.
RC TISSUE=Venom gland;
RX PubMed=19042943; DOI=10.1093/molbev/msn274;
RA Binford G.J., Bodner M.R., Cordes M.H., Baldwin K.L., Rynerson M.R.,
RA Burns S.N., Zobel-Thropp P.A.;
RT "Molecular evolution, functional variation, and proposed nomenclature of
RT the gene family that includes sphingomyelinase D in sicariid spider
RT venoms.";
RL Mol. Biol. Evol. 26:547-566(2009).
CC -!- FUNCTION: Dermonecrotic toxins cleave the phosphodiester linkage
CC between the phosphate and headgroup of certain phospholipids
CC (sphingolipid and lysolipid substrates), forming an alcohol (often
CC choline) and a cyclic phosphate (By similarity). This toxin acts on
CC sphingomyelin (SM) (By similarity). It may also act on ceramide
CC phosphoethanolamine (CPE), lysophosphatidylcholine (LPC) and
CC lysophosphatidylethanolamine (LPE), but not on lysophosphatidylserine
CC (LPS), and lysophosphatidylglycerol (LPG) (By similarity). It acts by
CC transphosphatidylation, releasing exclusively cyclic phosphate products
CC as second products (By similarity). Induces dermonecrosis, hemolysis,
CC increased vascular permeability, edema, inflammatory response, and
CC platelet aggregation (By similarity).
CC {ECO:0000250|UniProtKB:A0A0D4WTV1, ECO:0000250|UniProtKB:P0CE80}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=an N-(acyl)-sphingosylphosphocholine = an N-(acyl)-sphingosyl-
CC 1,3-cyclic phosphate + choline; Xref=Rhea:RHEA:60652,
CC ChEBI:CHEBI:15354, ChEBI:CHEBI:64583, ChEBI:CHEBI:143892;
CC Evidence={ECO:0000250|UniProtKB:A0A0D4WTV1};
CC -!- CATALYTIC ACTIVITY:
CC Reaction=an N-(acyl)-sphingosylphosphoethanolamine = an N-(acyl)-
CC sphingosyl-1,3-cyclic phosphate + ethanolamine; Xref=Rhea:RHEA:60648,
CC ChEBI:CHEBI:57603, ChEBI:CHEBI:143891, ChEBI:CHEBI:143892;
CC Evidence={ECO:0000250|UniProtKB:A0A0D4WTV1};
CC -!- CATALYTIC ACTIVITY:
CC Reaction=a 1-acyl-sn-glycero-3-phosphocholine = a 1-acyl-sn-glycero-
CC 2,3-cyclic phosphate + choline; Xref=Rhea:RHEA:60700,
CC ChEBI:CHEBI:15354, ChEBI:CHEBI:58168, ChEBI:CHEBI:143947;
CC Evidence={ECO:0000250|UniProtKB:A0A0D4WTV1};
CC -!- CATALYTIC ACTIVITY:
CC Reaction=a 1-acyl-sn-glycero-3-phosphoethanolamine = a 1-acyl-sn-
CC glycero-2,3-cyclic phosphate + ethanolamine; Xref=Rhea:RHEA:60704,
CC ChEBI:CHEBI:57603, ChEBI:CHEBI:64381, ChEBI:CHEBI:143947;
CC Evidence={ECO:0000250|UniProtKB:A0A0D4WTV1};
CC -!- COFACTOR:
CC Name=Mg(2+); Xref=ChEBI:CHEBI:18420;
CC Evidence={ECO:0000250|UniProtKB:Q8I914};
CC Note=Binds 1 Mg(2+) ion per subunit. {ECO:0000250|UniProtKB:Q8I914};
CC -!- SUBCELLULAR LOCATION: Secreted {ECO:0000305|PubMed:19042943}.
CC -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC {ECO:0000305|PubMed:19042943}.
CC -!- SIMILARITY: Belongs to the arthropod phospholipase D family. Class II
CC subfamily. {ECO:0000305}.
CC -!- CAUTION: The most common activity assay for dermonecrotic toxins
CC detects enzymatic activity by monitoring choline release from
CC substrate. Liberation of choline from sphingomyelin (SM) or
CC lysophosphatidylcholine (LPC) is commonly assumed to result from
CC substrate hydrolysis, giving either ceramide-1-phosphate (C1P) or
CC lysophosphatidic acid (LPA), respectively, as a second product.
CC However, two studies from Lajoie and colleagues (2013 and 2015) report
CC the observation of exclusive formation of cyclic phosphate products as
CC second products, resulting from intramolecular transphosphatidylation.
CC Cyclic phosphates have vastly different biological properties from
CC their monoester counterparts, and they may be relevant to the pathology
CC of brown spider envenomation. {ECO:0000250|UniProtKB:A0A0D4WTV1,
CC ECO:0000250|UniProtKB:A0A0D4WV12, ECO:0000250|UniProtKB:Q4ZFU2}.
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DR EMBL; FJ171424; ACN48920.2; -; mRNA.
DR AlphaFoldDB; C0JAY9; -.
DR SMR; C0JAY9; -.
DR GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR GO; GO:0016829; F:lyase activity; IEA:UniProtKB-KW.
DR GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR GO; GO:0008081; F:phosphoric diester hydrolase activity; IEA:InterPro.
DR GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR GO; GO:0044179; P:hemolysis in another organism; IEA:UniProtKB-KW.
DR GO; GO:0016042; P:lipid catabolic process; IEA:UniProtKB-KW.
DR Gene3D; 3.20.20.190; -; 1.
DR InterPro; IPR017946; PLC-like_Pdiesterase_TIM-brl.
DR SUPFAM; SSF51695; SSF51695; 1.
PE 2: Evidence at transcript level;
KW Cytolysis; Dermonecrotic toxin; Disulfide bond; Hemolysis;
KW Lipid degradation; Lipid metabolism; Lyase; Magnesium; Metal-binding;
KW Secreted; Toxin.
FT CHAIN <1..270
FT /note="Dermonecrotic toxin LsaSicTox-alphaIB1av"
FT /id="PRO_0000392779"
FT ACT_SITE 2
FT /evidence="ECO:0000250|UniProtKB:Q8I914"
FT ACT_SITE 38
FT /note="Nucleophile"
FT /evidence="ECO:0000250|UniProtKB:Q8I914"
FT BINDING 22
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /evidence="ECO:0000250|UniProtKB:Q8I914"
FT BINDING 24
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /evidence="ECO:0000250|UniProtKB:Q8I914"
FT BINDING 82
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /evidence="ECO:0000250|UniProtKB:Q8I914"
FT DISULFID 42..48
FT /evidence="ECO:0000250|UniProtKB:P0CE80"
FT DISULFID 44..187
FT /evidence="ECO:0000250|UniProtKB:P0CE80"
FT NON_TER 1
SQ SEQUENCE 270 AA; 30180 MW; 071A06335D918FA5 CRC64;
GHMVNAIAQI DEFVNLGANS IETDVSFDKN ANPEYTYHGI PCDCGRTCTK WEYFNTFLGG
LRKATTPGDS KYHEKLVLVV FDLKTGSLYD NQAYDAGTKL AKSLLQNYWN KGNNGGRAYI
VLSIPNLDHY KLITGFKETL TKEEHPELMD KVGYDFSGND DIGDVAKAYK KAGVTGHVWQ
SDGITNCLLR GLDRVRKAVA NRDSSNGYIN KVYYWTVDKR ASTRDALDAG VDGIMTNYPD
VIADVLSESA YTAKFRIATY DDNPWETFKN
