ID   KAX2G_CENTE             Reviewed;          39 AA.
AC   C0HJW6;
DT   06-JUL-2016, integrated into UniProtKB/Swiss-Prot.
DT   06-JUL-2016, sequence version 1.
DT   25-MAY-2022, entry version 14.
DE   RecName: Full=Potassium channel toxin alpha-KTx 2.16 {ECO:0000303|PubMed:26921461};
DE   AltName: Full=Toxin II.12.5 {ECO:0000303|PubMed:26921461};
OS   Centruroides tecomanus (Scorpion) (Centruroides limpidus tecomanus).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC   Scorpiones; Buthida; Buthoidea; Buthidae; Centruroides.
OX   NCBI_TaxID=1028682;
RN   [1]
RP   PROTEIN SEQUENCE, FUNCTION, SUBCELLULAR LOCATION, AND MASS SPECTROMETRY.
RC   TISSUE=Venom;
RX   PubMed=26921461; DOI=10.1016/j.toxicon.2016.02.017;
RA   Olamendi-Portugal T., Bartok A., Zamudio-Zuniga F., Balajthy A.,
RA   Becerril B., Panyi G., Possani L.D.;
RT   "Isolation, chemical and functional characterization of several new K(+)-
RT   channel blocking peptides from the venom of the scorpion Centruroides
RT   tecomanus.";
RL   Toxicon 115:1-12(2016).
CC   -!- FUNCTION: Blocks human voltage-gated potassium channels Kv1.2/KCNA2
CC       (IC(50)=0.7 nM), Kv1.3/KCNA3 (IC(50)=26.2 nM) and blocks intermediate
CC       conductance calcium-activated potassium channel KCa3.1/KCNN4 (IC(50)=56
CC       nM). {ECO:0000269|PubMed:26921461}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:26921461}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC       {ECO:0000305|PubMed:26921461}.
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:P08815}.
CC   -!- MASS SPECTROMETRY: Mass=4339.9; Method=Unknown;
CC       Evidence={ECO:0000269|PubMed:26921461};
CC   -!- MISCELLANEOUS: Does not block voltage-gated potassium channel
CC       Kv1.1/KCNA1 or the Shaker IR (with inactivation domain removed).
CC       {ECO:0000269|PubMed:26921461}.
CC   -!- SIMILARITY: Belongs to the short scorpion toxin superfamily. Potassium
CC       channel inhibitor family. Alpha-KTx 02 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; C0HJW6; -.
DR   SMR; C0HJW6; -.
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   PEPTIDE         1..39
FT                   /note="Potassium channel toxin alpha-KTx 2.16"
FT                   /evidence="ECO:0000269|PubMed:26921461"
FT                   /id="PRO_0000436537"
FT   SITE            28
FT                   /note="Basic residue of the functional dyad"
FT                   /evidence="ECO:0000250|UniProtKB:O46028"
FT   SITE            37
FT                   /note="Aromatic residue of the functional dyad"
FT                   /evidence="ECO:0000250|UniProtKB:O46028"
FT   MOD_RES         39
FT                   /note="Isoleucine amide"
FT                   /evidence="ECO:0000250|UniProtKB:P0C164"
FT   DISULFID        7..29
FT                   /evidence="ECO:0000250|UniProtKB:O46028"
FT   DISULFID        13..34
FT                   /evidence="ECO:0000250|UniProtKB:O46028"
FT   DISULFID        17..36
FT                   /evidence="ECO:0000250|UniProtKB:O46028"
SQ   SEQUENCE   39 AA;  4345 MW;  E469D54889860E10 CRC64;
     TIINVKCTSP KQCLKPCKDL YGPHAGEKCM NGKCKCYKI