ID   SCX4_ANDCR              Reviewed;          65 AA.
AC   M1JBC0;
DT   01-APR-2015, integrated into UniProtKB/Swiss-Prot.
DT   01-MAY-2013, sequence version 1.
DT   03-AUG-2022, entry version 24.
DE   RecName: Full=Sodium channel alpha-toxin Acra4;
DE   Flags: Precursor;
OS   Androctonus crassicauda (Arabian fat-tailed scorpion).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC   Scorpiones; Buthida; Buthoidea; Buthidae; Androctonus.
OX   NCBI_TaxID=122909;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA] OF 7-65, PROTEIN SEQUENCE OF 1-14, SUBCELLULAR
RP   LOCATION, MASS SPECTROMETRY, AND TOXIC DOSE.
RC   TISSUE=Venom, and Venom gland;
RX   PubMed=23395751; DOI=10.1016/j.biochi.2013.01.015;
RA   Caliskan F., Quintero-Hernandez V., Restano-Cassulini R.,
RA   Coronas-Valderrama F.I., Corzo G., Possani L.D.;
RT   "Molecular cloning and biochemical characterization of the first Na(+)-
RT   channel alpha-type toxin peptide (Acra4) from Androctonus crassicauda
RT   scorpion venom.";
RL   Biochimie 95:1216-1222(2013).
CC   -!- FUNCTION: Alpha toxins bind voltage-independently at site-3 of sodium
CC       channels (Nav) and inhibit the inactivation of the activated channels,
CC       thereby blocking neuronal transmission. Electrophysiological studies of
CC       this were performed using sodium-channels expressed in F11 cell
CC       culture, by patch-clamp recordings. Affinity of this toxin toward
CC       sodium channels in F11 cell line is in the order of 1 uM concentration.
CC       {ECO:0000269|PubMed:23395751}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:23395751}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland. {ECO:0000305}.
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   -!- MASS SPECTROMETRY: Mass=6937; Method=Electrospray;
CC       Evidence={ECO:0000269|PubMed:23395751};
CC   -!- TOXIC DOSE: LD(50) is 2.5 ug/kg when intracranially injected into mice.
CC       {ECO:0000269|PubMed:23395751}.
CC   -!- SIMILARITY: Belongs to the long (4 C-C) scorpion toxin superfamily.
CC       Sodium channel inhibitor family. Alpha subfamily. {ECO:0000305}.
CC   ---------------------------------------------------------------------------
CC   Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms
CC   Distributed under the Creative Commons Attribution (CC BY 4.0) License
CC   ---------------------------------------------------------------------------
DR   EMBL; JQ975126; AGE83103.1; -; mRNA.
DR   AlphaFoldDB; M1JBC0; -.
DR   SMR; M1JBC0; -.
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   Direct protein sequencing; Disulfide bond; Ion channel impairing toxin;
KW   Neurotoxin; Secreted; Toxin; Voltage-gated sodium channel impairing toxin.
FT   CHAIN           1..64
FT                   /note="Sodium channel alpha-toxin Acra4"
FT                   /id="PRO_5001113087"
FT   PROPEP          65
FT                   /note="Removed by a carboxypeptidase"
FT                   /evidence="ECO:0000250|UniProtKB:P01480"
FT                   /id="PRO_0000432477"
FT   DOMAIN          2..63
FT                   /note="LCN-type CS-alpha/beta"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        12..62
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        16..34
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        20..44
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        24..46
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
SQ   SEQUENCE   65 AA;  7101 MW;  E1CECC6B6EC862F1 CRC64;
     VRDGYIVDDK NCVYHCIPPC DGLCKKNGGK SGSCSFLVPS GLACWCKALP DNVPIKDPSY
     KCHKR