ID   KAX2B_CENEL             Reviewed;          39 AA.
AC   P0C164;
DT   07-MAR-2006, integrated into UniProtKB/Swiss-Prot.
DT   07-MAR-2006, sequence version 1.
DT   25-MAY-2022, entry version 48.
DE   RecName: Full=Potassium channel toxin alpha-KTx 2.11;
DE   AltName: Full=Toxin Ce4 {ECO:0000303|PubMed:16026809};
OS   Centruroides elegans (Bark scorpion).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC   Scorpiones; Buthida; Buthoidea; Buthidae; Centruroides.
OX   NCBI_TaxID=217897;
RN   [1]
RP   PROTEIN SEQUENCE, FUNCTION, MASS SPECTROMETRY, ACTIVITY PROFILE,
RP   SUBCELLULAR LOCATION, AND AMIDATION AT ILE-39.
RC   TISSUE=Venom;
RX   PubMed=16026809; DOI=10.1016/j.toxicon.2005.06.001;
RA   Olamendi-Portugal T., Somodi S., Fernandez J.A., Zamudio F.Z., Becerril B.,
RA   Varga Z., Panyi G., Gaspar R., Possani L.D.;
RT   "Novel alpha-KTx peptides from the venom of the scorpion Centruroides
RT   elegans selectively blockade Kv1.3 over IKCa1 K+ channels of T cells.";
RL   Toxicon 46:418-429(2005).
CC   -!- FUNCTION: Blocks Kv1.3/KCNA3 voltage-gated potassium channels of human
CC       T-lymphocytes (Kd=0.98 nM). {ECO:0000269|PubMed:16026809}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:16026809}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC       {ECO:0000305|PubMed:16026809}.
CC   -!- DOMAIN: Has the structural arrangement of an alpha-helix connected to a
CC       beta-sheet by disulfide bonds (CSalpha/beta).
CC       {ECO:0000250|UniProtKB:P40755}.
CC   -!- MASS SPECTROMETRY: Mass=4295; Method=Electrospray;
CC       Evidence={ECO:0000269|PubMed:16026809};
CC   -!- MISCELLANEOUS: Does not inhibit calcium-activated potassium channels
CC       (KCa3.1/KCNN4) of human T-lymphocytes. Does not inhibit voltage-gated
CC       Shaker potassium channels. Does not inhibit Kv2.1/KCNB1 potassium
CC       channels. {ECO:0000269|PubMed:16026809}.
CC   -!- SIMILARITY: Belongs to the short scorpion toxin superfamily. Potassium
CC       channel inhibitor family. Alpha-KTx 02 subfamily. {ECO:0000305}.
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DR   AlphaFoldDB; P0C164; -.
DR   SMR; P0C164; -.
DR   TCDB; 8.B.8.1.4; the Alpha-ktx15 scorpion toxin (Alpha-ktx15) family.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0008200; F:ion channel inhibitor activity; IEA:InterPro.
DR   GO; GO:0015459; F:potassium channel regulator activity; IEA:UniProtKB-KW.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
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   Amidation; Direct protein sequencing; Disulfide bond;
KW   Ion channel impairing toxin; Neurotoxin; Potassium channel impairing toxin;
KW   Secreted; Toxin; Voltage-gated potassium channel impairing toxin.
FT   CHAIN           1..39
FT                   /note="Potassium channel toxin alpha-KTx 2.11"
FT                   /evidence="ECO:0000269|PubMed:16026809"
FT                   /id="PRO_0000226961"
FT   SITE            28
FT                   /note="Basic residue of the functional dyad"
FT                   /evidence="ECO:0000250"
FT   SITE            37
FT                   /note="Aromatic residue of the functional dyad"
FT                   /evidence="ECO:0000250"
FT   MOD_RES         39
FT                   /note="Isoleucine amide"
FT                   /evidence="ECO:0000269|PubMed:16026809"
FT   DISULFID        7..29
FT                   /evidence="ECO:0000250|UniProtKB:P59847"
FT   DISULFID        13..34
FT                   /evidence="ECO:0000250|UniProtKB:P59847"
FT   DISULFID        17..36
FT                   /evidence="ECO:0000250|UniProtKB:P59847"
SQ   SEQUENCE   39 AA;  4302 MW;  F1AE524E3BF97E10 CRC64;
     TIINVKCTSP KQCLLPCKEI YGIHAGAKCM NGKCKCYKI