ID   SCXM1_MESMA             Reviewed;          86 AA.
AC   A0F0C2; Q95P87;
DT   19-MAR-2014, integrated into UniProtKB/Swiss-Prot.
DT   19-MAR-2014, sequence version 2.
DT   25-MAY-2022, entry version 48.
DE   RecName: Full=Mesotoxin-1;
DE   Flags: Precursor;
OS   Mesobuthus martensii (Manchurian scorpion) (Buthus martensii).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC   Scorpiones; Buthida; Buthoidea; Buthidae; Mesobuthus.
OX   NCBI_TaxID=34649;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA], VARIANT MESOTOXIN-2 ASP-74, VARIANT
RP   MESOTOXIN-3 ALA-77, AND 3D-STRUCTURE MODELING.
RX   PubMed=17054952; DOI=10.1016/j.febslet.2006.09.071;
RA   Zhu S., Gao B.;
RT   "Molecular characterization of a possible progenitor sodium channel toxin
RT   from the Old World scorpion Mesobuthus martensii.";
RL   FEBS Lett. 580:5979-5987(2006).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [MRNA] OF 41-86.
RC   TISSUE=Venom gland;
RA   Zhu S., Li W.;
RT   "cDNA encoding a toxin-like peptide from BmK.";
RL   Submitted (JUN-1999) to the EMBL/GenBank/DDBJ databases.
CC   -!- FUNCTION: Binds to sodium channels (Nav) and affects the channel
CC       activation process. {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000250}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
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   -!- SIMILARITY: Belongs to the long (3 C-C) scorpion toxin superfamily.
CC       Sodium channel inhibitor family. Beta subfamily. {ECO:0000305}.
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DR   EMBL; DQ872676; ABJ09780.1; -; Genomic_DNA.
DR   EMBL; AF159977; AAK61824.1; -; mRNA.
DR   AlphaFoldDB; A0F0C2; -.
DR   SMR; A0F0C2; -.
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   SUPFAM; SSF57095; SSF57095; 1.
DR   PROSITE; PS51863; LCN_CSAB; 1.
PE   3: Inferred from homology;
KW   Disulfide bond; Ion channel impairing toxin; Neurotoxin; Secreted; Signal;
KW   Toxin; Voltage-gated sodium channel impairing toxin.
FT   SIGNAL          1..22
FT                   /evidence="ECO:0000255"
FT   CHAIN           23..86
FT                   /note="Mesotoxin-1"
FT                   /id="PRO_0000425735"
FT   DOMAIN          24..86
FT                   /note="LCN-type CS-alpha/beta"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        37..61
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        47..66
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        51..68
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   VARIANT         74
FT                   /note="N -> D (in mesotoxin-2)"
FT                   /evidence="ECO:0000269|PubMed:17054952"
FT   VARIANT         77
FT                   /note="T -> A (in mesotoxin-3)"
FT                   /evidence="ECO:0000269|PubMed:17054952"
SQ   SEQUENCE   86 AA;  9959 MW;  5A4A568D0F361D8F CRC64;
     MKILTVFMIF IANFLNMMQV FSVKDRFLII NGSYELCVYA ENLGEDCENL CKQQKATDGF
     CRQPHCFCTD MPDNYATRPD TVDPIM