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 22-FEB-2023, entry version 58. 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}. 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; 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; Knottin, scorpion toxin-like; 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; Scorpion toxin-like; 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 //