ID   SCX1_HOTTA              Reviewed;          64 AA.
AC   P60277; Q45TB5;
DT   16-JAN-2004, integrated into UniProtKB/Swiss-Prot.
DT   16-JAN-2004, sequence version 1.
DT   03-AUG-2022, entry version 66.
DE   RecName: Full=Neurotoxin BTN;
OS   Hottentotta tamulus (Eastern Indian scorpion) (Mesobuthus tamulus).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC   Scorpiones; Buthida; Buthoidea; Buthidae; Mesobuthus.
OX   NCBI_TaxID=34647;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA], AND X-RAY CRYSTALLOGRAPHY (2.2 ANGSTROMS).
RX   PubMed=16677826; DOI=10.1016/j.jsb.2005.12.005;
RA   Sharma M., Ethayathulla A.S., Jabeen T., Singh N., Sarvanan K., Yadav S.,
RA   Sharma S., Srinivasan A., Singh T.P.;
RT   "Crystal structure of a highly acidic neurotoxin from scorpion Buthus
RT   tamulus at 2.2-A resolution reveals novel structural features.";
RL   J. Struct. Biol. 155:52-62(2006).
CC   -!- FUNCTION: Inhibits sodium channels (Nav). {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: Secreted.
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 (4 C-C) scorpion toxin superfamily.
CC       Sodium channel inhibitor family. Alpha subfamily. {ECO:0000305}.
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DR   EMBL; DQ116789; AAZ20273.1; -; mRNA.
DR   PDB; 1DQ7; X-ray; 2.20 A; A/B=1-64.
DR   PDB; 2A7T; X-ray; 2.20 A; A/B=1-64.
DR   PDBsum; 1DQ7; -.
DR   PDBsum; 2A7T; -.
DR   AlphaFoldDB; P60277; -.
DR   SMR; P60277; -.
DR   EvolutionaryTrace; P60277; -.
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; 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; Disulfide bond; Ion channel impairing toxin; Neurotoxin;
KW   Secreted; Toxin; Voltage-gated sodium channel impairing toxin.
FT   CHAIN           1..64
FT                   /note="Neurotoxin BTN"
FT                   /id="PRO_0000066757"
FT   DOMAIN          2..64
FT                   /note="LCN-type CS-alpha/beta"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        12..63
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        16..36
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        22..46
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        26..48
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   STRAND          2..4
FT                   /evidence="ECO:0007829|PDB:1DQ7"
FT   HELIX           19..28
FT                   /evidence="ECO:0007829|PDB:1DQ7"
FT   STRAND          32..40
FT                   /evidence="ECO:0007829|PDB:1DQ7"
FT   STRAND          43..51
FT                   /evidence="ECO:0007829|PDB:1DQ7"
SQ   SEQUENCE   64 AA;  7041 MW;  06A852E2F5B0B934 CRC64;
     GEDGYIADGD NCTYICTFNN YCHALCTDKK GDSGACDWWV PYGVVCWCED LPTPVPIRGS
     GKCR