ID   SCX2_TITFA              Reviewed;          84 AA.
AC   C0HJM9;
DT   07-JUN-2017, integrated into UniProtKB/Swiss-Prot.
DT   07-JUN-2017, sequence version 1.
DT   03-AUG-2022, entry version 14.
DE   RecName: Full=Toxin Tf2 {ECO:0000303|PubMed:26083731};
DE   Flags: Precursor;
OS   Tityus fasciolatus (Central Brazilian scorpion).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC   Scorpiones; Buthida; Buthoidea; Buthidae; Tityus.
OX   NCBI_TaxID=203543;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA], PROTEIN SEQUENCE OF 21-82, FUNCTION,
RP   SUBCELLULAR LOCATION, PRESENCE OF DISULFIDE BONDS, MASS SPECTROMETRY, AND
RP   AMIDATION AT CYS-82.
RC   TISSUE=Venom;
RX   PubMed=26083731; DOI=10.1371/journal.pone.0128578;
RA   Camargos T.S., Bosmans F., Rego S.C., Mourao C.B., Schwartz E.F.;
RT   "The Scorpion Toxin Tf2 from Tityus fasciolatus Promotes Nav1.3 Opening.";
RL   PLoS ONE 10:E0128578-E0128578(2015).
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. This toxin is active against
CC       hNav1.3/SCN3A. {ECO:0000269|PubMed:26083731}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:26083731}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC       {ECO:0000305|PubMed:26083731}.
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   -!- PTM: Contains 4 disulfide bonds. {ECO:0000269|PubMed:26083731}.
CC   -!- MASS SPECTROMETRY: Mass=6949.935; Method=Electrospray;
CC       Evidence={ECO:0000269|PubMed:26083731};
CC   -!- MISCELLANEOUS: This toxin does not affect mammalian sodium channels
CC       Nav1.1/SCN1A, Nav1.2/SCN2A, Nav1.4/SCN4A, Nav1.5/SCN5A, Nav1.6/SCN8A,
CC       Nav1.7/SCN9A and Nav1.8/SCN10A. {ECO:0000269|PubMed:26083731}.
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   AlphaFoldDB; C0HJM9; -.
DR   SMR; C0HJM9; -.
DR   GO; GO:0005576; C:extracellular region; IDA:UniProtKB.
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   GO; GO:0044493; P:envenomation resulting in negative regulation of voltage-gated sodium channel activity in another organism; IDA:UniProtKB.
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   Amidation; Direct protein sequencing; Disulfide bond;
KW   Ion channel impairing toxin; Neurotoxin; Secreted; Signal; Toxin;
KW   Voltage-gated sodium channel impairing toxin.
FT   SIGNAL          1..20
FT                   /evidence="ECO:0000269|PubMed:26083731"
FT   CHAIN           21..82
FT                   /note="Toxin Tf2"
FT                   /evidence="ECO:0000269|PubMed:26083731"
FT                   /id="PRO_0000440617"
FT   DOMAIN          21..83
FT                   /note="LCN-type CS-alpha/beta"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   MOD_RES         82
FT                   /note="Cysteine amide"
FT                   /evidence="ECO:0000269|PubMed:26083731"
FT   DISULFID        31..82
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        35..58
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        43..63
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        47..65
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
SQ   SEQUENCE   84 AA;  9413 MW;  C2AD766B187A6860 CRC64;
     MKRFLLFISI LMMIGTIVVG KEGYAMDHEG CKFSCFIRPS GFCDGYCKTH LKASSGYCAW
     PACYCYGVPS NIKVWDYATN KCGK