ID   SCXN3_MESEU             Reviewed;          82 AA.
AC   E7CZY8;
DT   03-JUL-2019, integrated into UniProtKB/Swiss-Prot.
DT   08-MAR-2011, sequence version 1.
DT   25-MAY-2022, entry version 32.
DE   RecName: Full=Sodium channel neurotoxin MeuNaTxalpha-3 {ECO:0000303|PubMed:21969612};
DE   Flags: Precursor; Fragment;
OS   Mesobuthus eupeus (Lesser Asian scorpion) (Buthus eupeus).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC   Scorpiones; Buthida; Buthoidea; Buthidae; Mesobuthus.
OX   NCBI_TaxID=34648;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA], MASS SPECTROMETRY, AND SUBCELLULAR LOCATION.
RC   TISSUE=Venom, and Venom gland;
RX   PubMed=21969612; DOI=10.1074/mcp.m111.012054;
RA   Zhu S., Peigneur S., Gao B., Lu X., Cao C., Tytgat J.;
RT   "Evolutionary diversification of Mesobuthus alpha-scorpion toxins affecting
RT   sodium channels.";
RL   Mol. Cell. Proteomics 11:M111.012054-M111.012054(2012).
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. {ECO:0000250|UniProtKB:P86405}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:21969612}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC       {ECO:0000305|PubMed:21969612}.
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=8299.90; Method=MALDI;
CC       Evidence={ECO:0000269|PubMed:21969612};
CC   -!- SIMILARITY: Belongs to the long (4 C-C) scorpion toxin superfamily.
CC       Sodium channel inhibitor family. Alpha subfamily. {ECO:0000305}.
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DR   EMBL; HM989911; ADT82851.1; -; mRNA.
DR   AlphaFoldDB; E7CZY8; -.
DR   SMR; E7CZY8; -.
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   CDD; cd00107; Knot1; 1.
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; IPR002061; Scorpion_toxinL/defensin.
DR   Pfam; PF00537; Toxin_3; 1.
DR   SMART; SM00505; Knot1; 1.
DR   SUPFAM; SSF57095; SSF57095; 1.
DR   PROSITE; PS51863; LCN_CSAB; 1.
PE   1: Evidence at protein level;
KW   Disulfide bond; Ion channel impairing toxin; Neurotoxin; Secreted; Signal;
KW   Toxin; Voltage-gated sodium channel impairing toxin.
FT   SIGNAL          <1..8
FT                   /evidence="ECO:0000305"
FT   CHAIN           9..82
FT                   /note="Sodium channel neurotoxin MeuNaTxalpha-3"
FT                   /evidence="ECO:0000305|PubMed:21969612"
FT                   /id="PRO_0000447445"
FT   DOMAIN          10..80
FT                   /note="LCN-type CS-alpha/beta"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        20..79
FT                   /evidence="ECO:0000250|UniProtKB:P86405"
FT   DISULFID        24..52
FT                   /evidence="ECO:0000250|UniProtKB:P86405"
FT   DISULFID        38..62
FT                   /evidence="ECO:0000250|UniProtKB:P86405"
FT   DISULFID        42..64
FT                   /evidence="ECO:0000250|UniProtKB:P86405"
FT   NON_TER         1
SQ   SEQUENCE   82 AA;  9093 MW;  AFB01E2B79051AF8 CRC64;
     LVMAGVESGR DGHIARNNNC VYVCFIEYTY IGTSRINCND LCTKNGAKSG YCHQFSEYGN
     SCWCIDLPDN VPIKVPGDCH LQ