KAX88_ORTSC
ID KAX88_ORTSC Reviewed; 57 AA.
AC A0A1L2FZD4; C0HK17;
DT 12-APR-2017, integrated into UniProtKB/Swiss-Prot.
DT 15-MAR-2017, sequence version 1.
DT 25-MAY-2022, entry version 10.
DE RecName: Full=Potassium channel toxin alpha-KTx 8.8 {ECO:0000303|PubMed:28179135};
DE AltName: Full=OSK3 {ECO:0000303|PubMed:28179135};
DE Flags: Precursor;
OS Orthochirus scrobiculosus (Central Asian scorpion).
OC Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC Scorpiones; Buthida; Buthoidea; Buthidae; Orthochirus.
OX NCBI_TaxID=6892;
RN [1]
RP NUCLEOTIDE SEQUENCE [MRNA], PROTEIN SEQUENCE OF 29-57, FUNCTION,
RP SUBCELLULAR LOCATION, PRESENCE OF DISULFIDE BONDS, AND MASS SPECTROMETRY.
RC TISSUE=Venom, and Venom gland;
RX PubMed=28179135; DOI=10.1016/j.bbapap.2017.02.001;
RA Kuzmenkov A.I., Peigneur S., Chugunov A.O., Tabakmakher V.M., Efremov R.G.,
RA Tytgat J., Grishin E.V., Vassilevski A.A.;
RT "C-Terminal residues in small potassium channel blockers OdK1 and OSK3 from
RT scorpion venom fine-tune the selectivity.";
RL Biochim. Biophys. Acta 1865:465-472(2017).
CC -!- FUNCTION: Selectively inhibits voltage-gated potassium channels
CC rKv1.2/KCNA2 (IC(50)=331 nM) and hKv1.3/KCNA3 (IC(50)=503 nM).
CC Partially inihibts rKv1.6/KCNA6 (IC(50)=9983 nM).
CC {ECO:0000269|PubMed:28179135}.
CC -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:28179135}.
CC -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC {ECO:0000305|PubMed:28179135}.
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:P56215}.
CC -!- PTM: Contains 3 disulfide bonds. {ECO:0000269|PubMed:28179135}.
CC -!- MASS SPECTROMETRY: Mass=3206.3; Mass_error=0.2; Method=MALDI;
CC Evidence={ECO:0000269|PubMed:28179135};
CC -!- MISCELLANEOUS: This toxin does not affect the following channels:
CC rKv1.1/KCNA1, rKv1.4/KCNA4, rKv1.5/KCNA5, Shaker IR (with inactivation
CC domain removed), rKv2.1/KCNB1, hKv3.1/KCNC1, rKv4.2/KCND2 and
CC hKv11.1/KCNH2/ERG1. {ECO:0000269|PubMed:28179135}.
CC -!- SIMILARITY: Belongs to the short scorpion toxin superfamily. Potassium
CC channel inhibitor family. Alpha-KTx 08 subfamily. {ECO:0000305}.
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DR EMBL; KX355614; AOG62199.1; -; mRNA.
DR AlphaFoldDB; A0A1L2FZD4; -.
DR SMR; A0A1L2FZD4; -.
DR GO; GO:0005576; C:extracellular region; IDA:UniProtKB.
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 GO; GO:0044361; P:negative regulation of voltage-gated potassium channel activity in another organism; IDA:UniProtKB.
DR InterPro; IPR036574; Scorpion_toxin-like_sf.
DR InterPro; IPR008911; Toxin_alpha-KTx_8/9.
DR Pfam; PF05453; Toxin_6; 1.
DR SUPFAM; SSF57095; SSF57095; 1.
PE 1: Evidence at protein level;
KW Direct protein sequencing; Disulfide bond; Ion channel impairing toxin;
KW Potassium channel impairing toxin; Secreted; Signal; Toxin;
KW Voltage-gated potassium channel impairing toxin.
FT SIGNAL 1..19
FT /evidence="ECO:0000255"
FT PROPEP 20..28
FT /evidence="ECO:0000305|PubMed:28179135"
FT /id="PRO_0000439599"
FT PEPTIDE 29..57
FT /note="Potassium channel toxin alpha-KTx 8.8"
FT /evidence="ECO:0000269|PubMed:28179135"
FT /id="PRO_0000439600"
FT DISULFID 31..47
FT /evidence="ECO:0000250|UniProtKB:P56215"
FT DISULFID 34..52
FT /evidence="ECO:0000250|UniProtKB:P56215"
FT DISULFID 38..54
FT /evidence="ECO:0000250|UniProtKB:P56215"
SQ SEQUENCE 57 AA; 6386 MW; A84D78A2DD492917 CRC64;
MCRLYAIILI VLVMNVIMTI IPDSKVEVVS CEDCPEHCST QKARAKCDND KCVCEPI