ID   KAX44_TITOB             Reviewed;          37 AA.
AC   P60210;
DT   16-JAN-2004, integrated into UniProtKB/Swiss-Prot.
DT   16-JAN-2004, sequence version 1.
DT   25-MAY-2022, entry version 56.
DE   RecName: Full=Potassium channel toxin alpha-KTx 4.4;
DE   AltName: Full=Toxin Tc30;
DE   AltName: Full=Toxin To30;
OS   Tityus obscurus (Amazonian scorpion) (Tityus cambridgei).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC   Scorpiones; Buthida; Buthoidea; Buthidae; Tityus.
OX   NCBI_TaxID=1221240;
RN   [1]
RP   PROTEIN SEQUENCE, FUNCTION, AND MASS SPECTROMETRY.
RC   TISSUE=Venom;
RX   PubMed=12445473; DOI=10.1016/s1570-9639(02)00458-2;
RA   Batista C.V.F., Gomez-Lagunas F., Rodriguez de la Vega R.C., Hajdu P.,
RA   Panyi G., Gaspar R., Possani L.D.;
RT   "Two novel toxins from the Amazonian scorpion Tityus cambridgei that block
RT   Kv1.3 and Shaker B K(+)-channels with distinctly different affinities.";
RL   Biochim. Biophys. Acta 1601:123-131(2002).
RN   [2]
RP   PROTEIN SEQUENCE OF 1-10, SUBCELLULAR LOCATION, TISSUE SPECIFICITY, AND
RP   MASS SPECTROMETRY.
RC   TISSUE=Venom;
RX   PubMed=15025998; DOI=10.1016/j.jchromb.2003.09.002;
RA   Batista C.V.F., del Pozo L., Zamudio F.Z., Contreras S., Becerril B.,
RA   Wanke E., Possani L.D.;
RT   "Proteomics of the venom from the Amazonian scorpion Tityus cambridgei and
RT   the role of prolines on mass spectrometry analysis of toxins.";
RL   J. Chromatogr. B 803:55-66(2004).
CC   -!- FUNCTION: Reversible blocker of both Shaker B potassium channels (high
CC       affinity), and Kv1.3/KCNA3 potassium channels of human T lymphocytes
CC       (low affinity). {ECO:0000269|PubMed:12445473}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:15025998}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC       {ECO:0000269|PubMed:15025998}.
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=3871.8; Method=Electrospray;
CC       Evidence={ECO:0000269|PubMed:12445473, ECO:0000269|PubMed:15025998};
CC   -!- SIMILARITY: Belongs to the short scorpion toxin superfamily. Potassium
CC       channel inhibitor family. Alpha-KTx 04 subfamily. {ECO:0000305}.
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DR   AlphaFoldDB; P60210; -.
DR   SMR; P60210; -.
DR   GO; GO:0005576; C:extracellular region; HDA:UniProtKB.
DR   GO; GO:0019870; F:potassium channel inhibitor activity; IDA:UniProtKB.
DR   GO; GO:0090729; F:toxin activity; IDA:UniProtKB.
DR   GO; GO:0044361; P:negative regulation of voltage-gated potassium channel activity in another organism; IDA:UniProtKB.
DR   Gene3D; 3.30.30.10; -; 1.
DR   InterPro; IPR036574; Scorpion_toxin-like_sf.
DR   InterPro; IPR001947; Scorpion_toxinS_K_inh.
DR   Pfam; PF00451; Toxin_2; 1.
DR   PRINTS; PR00286; CHARYBDTOXIN.
DR   SUPFAM; SSF57095; SSF57095; 1.
DR   PROSITE; PS01138; SCORP_SHORT_TOXIN; 1.
PE   1: Evidence at protein level;
KW   Direct protein sequencing; Disulfide bond; Ion channel impairing toxin;
KW   Neurotoxin; Potassium channel impairing toxin; Secreted; Toxin;
KW   Voltage-gated potassium channel impairing toxin.
FT   PEPTIDE         1..37
FT                   /note="Potassium channel toxin alpha-KTx 4.4"
FT                   /id="PRO_0000044920"
FT   REGION          26..33
FT                   /note="Interaction with Ca(2+)-activated K(+) channels"
FT                   /evidence="ECO:0000255"
FT   SITE            27
FT                   /note="Basic residue of the functional dyad"
FT                   /evidence="ECO:0000250"
FT   SITE            36
FT                   /note="Aromatic residue of the functional dyad"
FT                   /evidence="ECO:0000250"
FT   DISULFID        7..28
FT                   /evidence="ECO:0000250"
FT   DISULFID        13..33
FT                   /evidence="ECO:0000250"
FT   DISULFID        17..35
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   37 AA;  3878 MW;  6B17BB651C3E3449 CRC64;
     VFINVKCRGS KECLPACKAA VGKAAGKCMN GKCKCYP