ID   SCXX_CENNO              Reviewed;          87 AA.
AC   P45664;
DT   01-NOV-1995, integrated into UniProtKB/Swiss-Prot.
DT   01-NOV-1995, sequence version 1.
DT   03-AUG-2022, entry version 80.
DE   RecName: Full=Toxin CngtIII;
DE   Flags: Precursor;
OS   Centruroides noxius (Mexican scorpion).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC   Scorpiones; Buthida; Buthoidea; Buthidae; Centruroides.
OX   NCBI_TaxID=6878;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RC   TISSUE=Venom gland;
RX   PubMed=8390386; DOI=10.1016/0378-1119(93)90559-l;
RA   Becerril B., Vazquez A., Garcia C., Corona M., Bolivar F., Possani L.D.;
RT   "Cloning and characterization of cDNAs that code for Na(+)-channel-blocking
RT   toxins of the scorpion Centruroides noxius Hoffmann.";
RL   Gene 128:165-171(1993).
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. {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. Beta 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; L05061; AAA28286.1; -; mRNA.
DR   PIR; JN0670; JN0670.
DR   AlphaFoldDB; P45664; -.
DR   SMR; P45664; -.
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   2: Evidence at transcript level;
KW   Disulfide bond; Ion channel impairing toxin; Neurotoxin; Secreted; Signal;
KW   Toxin; Voltage-gated sodium channel impairing toxin.
FT   SIGNAL          1..19
FT                   /evidence="ECO:0000250"
FT   CHAIN           20..87
FT                   /note="Toxin CngtIII"
FT                   /id="PRO_0000035284"
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:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        35..60
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        44..65
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        48..67
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
SQ   SEQUENCE   87 AA;  9587 MW;  F172AA6162C406A3 CRC64;
     MNSLLMITAC LVLFGTVWAK EGYLVNKSTG CKYGCFWLGK NEGCDKECKA KNQGGSYGYC
     YAFGCWCEGL PESTPTYPLP NKTCSKK