SCX2_CENSC
ID SCX2_CENSC Reviewed; 87 AA.
AC P01493; Q95WC2; Q95WC3; Q95WC4; Q95WC5; Q95WC8;
DT 21-JUL-1986, integrated into UniProtKB/Swiss-Prot.
DT 21-JUL-1986, sequence version 2.
DT 03-AUG-2022, entry version 114.
DE RecName: Full=Toxin CsEv2 {ECO:0000303|PubMed:11600153};
DE Short=CsE-v2 {ECO:0000303|PubMed:11847271};
DE AltName: Full=Neurotoxin 2 {ECO:0000303|PubMed:4460885};
DE Flags: Precursor;
OS Centruroides sculpturatus (Arizona bark scorpion).
OC Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC Scorpiones; Buthida; Buthoidea; Buthidae; Centruroides.
OX NCBI_TaxID=218467;
RN [1]
RP NUCLEOTIDE SEQUENCE [MRNA].
RC TISSUE=Venom gland;
RX PubMed=11600153; DOI=10.1016/s0041-0101(01)00174-x;
RA Corona M., Valdez-Cruz N.A., Merino E., Zurita M., Possani L.D.;
RT "Genes and peptides from the scorpion Centruroides sculpturatus Ewing, that
RT recognize Na(+)-channels.";
RL Toxicon 39:1893-1898(2001).
RN [2]
RP PROTEIN SEQUENCE OF 20-85, FUNCTION, SUBCELLULAR LOCATION, TISSUE
RP SPECIFICITY, AND TOXIC DOSE.
RC TISSUE=Venom;
RX PubMed=4460885; DOI=10.1016/0003-9861(74)90082-4;
RA Babin D.R., Watt D.D., Goos S.M., Mlejnek R.V.;
RT "Amino acid sequences of neurotoxic protein variants from the venom of
RT Centruroides sculpturatus Ewing.";
RL Arch. Biochem. Biophys. 164:694-706(1974).
RN [3]
RP X-RAY CRYSTALLOGRAPHY (2.2 ANGSTROMS) OF 20-85, AND DISULFIDE BONDS.
RC TISSUE=Venom;
RX PubMed=11847271; DOI=10.1110/ps.39202;
RA Cook W.J., Zell A., Watt D.D., Ealick S.E.;
RT "Structure of variant 2 scorpion toxin from Centruroides sculpturatus
RT Ewing.";
RL Protein Sci. 11:479-486(2002).
CC -!- FUNCTION: Beta toxins bind voltage-independently at site-4 of sodium
CC channels (Nav) and shift the voltage of activation toward more negative
CC potentials thereby affecting sodium channel activation and promoting
CC spontaneous and repetitive firing (By similarity). Induces immediate
CC paralysis in crickets after injection, with a total paralysis occurring
CC within 15-30 minutes and lasting for 1-2 hours. Is also lethal to
CC vertebrate (chicks) when injected in very high dosages (more that 100
CC mg/kg). {ECO:0000250, ECO:0000269|PubMed:4460885}.
CC -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:4460885}.
CC -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC {ECO:0000269|PubMed:4460885}.
CC -!- DOMAIN: Has the structural arrangement of an alpha-helix connected to
CC antiparallel beta-sheets by disulfide bonds (CS-alpha/beta).
CC {ECO:0000305}.
CC -!- TOXIC DOSE: PD(50) is 21.5 mg/kg of insects (crickets).
CC {ECO:0000269|PubMed:4460885}.
CC -!- SIMILARITY: Belongs to the long (4 C-C) scorpion toxin superfamily.
CC Sodium channel inhibitor family. Beta subfamily. {ECO:0000305}.
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DR EMBL; AF338453; AAL23421.1; -; mRNA.
DR EMBL; AF338456; AAL23424.1; -; mRNA.
DR EMBL; AF338457; AAL23425.1; -; mRNA.
DR EMBL; AF338458; AAL23426.1; -; mRNA.
DR EMBL; AF338459; AAL23427.1; -; mRNA.
DR PDB; 1JZA; X-ray; 2.20 A; A/B=20-85.
DR PDB; 1JZB; X-ray; 2.81 A; A=20-85.
DR PDBsum; 1JZA; -.
DR PDBsum; 1JZB; -.
DR AlphaFoldDB; P01493; -.
DR SMR; P01493; -.
DR EvolutionaryTrace; P01493; -.
DR GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR GO; GO:0019871; F:sodium channel inhibitor activity; IEA:InterPro.
DR GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR GO; GO:0006952; P:defense response; IEA:InterPro.
DR Gene3D; 3.30.30.10; -; 1.
DR InterPro; IPR044062; LCN-type_CS_alpha_beta_dom.
DR InterPro; IPR003614; Scorpion_toxin-like.
DR InterPro; IPR036574; Scorpion_toxin-like_sf.
DR InterPro; IPR018218; Scorpion_toxinL.
DR InterPro; IPR002061; Scorpion_toxinL/defensin.
DR Pfam; PF00537; Toxin_3; 1.
DR PRINTS; PR00285; SCORPNTOXIN.
DR SMART; SM00505; Knot1; 1.
DR SUPFAM; SSF57095; SSF57095; 1.
DR PROSITE; PS51863; LCN_CSAB; 1.
PE 1: Evidence at protein level;
KW 3D-structure; Direct protein sequencing; Disulfide bond;
KW Ion channel impairing toxin; Neurotoxin; Secreted; Signal; Toxin;
KW Voltage-gated sodium channel impairing toxin.
FT SIGNAL 1..19
FT /evidence="ECO:0000269|PubMed:4460885"
FT PEPTIDE 20..85
FT /note="Toxin CsEv2"
FT /id="PRO_0000035289"
FT DOMAIN 20..85
FT /note="LCN-type CS-alpha/beta"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT DISULFID 31..84
FT /evidence="ECO:0000269|PubMed:11847271,
FT ECO:0007744|PDB:1JZA, ECO:0007744|PDB:1JZB"
FT DISULFID 35..60
FT /evidence="ECO:0000269|PubMed:11847271,
FT ECO:0007744|PDB:1JZA, ECO:0007744|PDB:1JZB"
FT DISULFID 44..65
FT /evidence="ECO:0000269|PubMed:11847271,
FT ECO:0007744|PDB:1JZA, ECO:0007744|PDB:1JZB"
FT DISULFID 48..67
FT /evidence="ECO:0000269|PubMed:11847271,
FT ECO:0007744|PDB:1JZA, ECO:0007744|PDB:1JZB"
FT VARIANT 6
FT /note="I -> M (in CsEv2B and CsEv2D)"
FT VARIANT 11..14
FT /note="LFLI -> FALV (in CsEv2A*)"
FT VARIANT 20
FT /note="K -> R (in CsEv2B)"
FT VARIANT 30
FT /note="G -> A (in CsEv2D)"
FT VARIANT 51
FT /note="K -> E (in CsEv2C)"
FT CONFLICT 44..46
FT /note="CDK -> NKC (in Ref. 2; AA sequence)"
FT /evidence="ECO:0000305"
FT CONFLICT 83..84
FT /note="SC -> CS (in Ref. 2; AA sequence)"
FT /evidence="ECO:0000305"
FT TURN 27..29
FT /evidence="ECO:0007829|PDB:1JZA"
FT HELIX 42..49
FT /evidence="ECO:0007829|PDB:1JZA"
FT TURN 51..53
FT /evidence="ECO:0007829|PDB:1JZA"
FT STRAND 56..60
FT /evidence="ECO:0007829|PDB:1JZA"
FT STRAND 62..69
FT /evidence="ECO:0007829|PDB:1JZA"
FT STRAND 77..79
FT /evidence="ECO:0007829|PDB:1JZA"
SQ SEQUENCE 87 AA; 9520 MW; 760810C65269B74E CRC64;
MNSLLIITAC LFLIGTVWAK EGYLVNKSTG CKYGCLKLGE NEGCDKECKA KNQGGSYGYC
YAFACWCEGL PESTPTYPLP NKSCSRK
