KAX1A_PARTR
ID KAX1A_PARTR Reviewed; 37 AA.
AC P83112;
DT 19-DEC-2001, integrated into UniProtKB/Swiss-Prot.
DT 01-OCT-2001, sequence version 1.
DT 25-MAY-2022, entry version 73.
DE RecName: Full=Potassium channel toxin alpha-KTx 1.10 {ECO:0000303|PubMed:11952787};
DE AltName: Full=Parabutoxin-3 {ECO:0000303|PubMed:11952787};
DE Short=PBTx3 {ECO:0000303|PubMed:11952787};
OS Parabuthus transvaalicus (South African fattail scorpion).
OC Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC Scorpiones; Buthida; Buthoidea; Buthidae; Parabuthus.
OX NCBI_TaxID=170972;
RN [1]
RP PROTEIN SEQUENCE, FUNCTION, SUBCELLULAR LOCATION, NOMENCLATURE, AND
RP ACTIVITY PROFILE.
RC TISSUE=Venom;
RX PubMed=11952787; DOI=10.1046/j.1432-1033.2002.02833.x;
RA Huys I., Dyason K., Waelkens E., Verdonck F., van Zyl J., du Plessis J.,
RA Mueller G.J., van der Walt J., Clynen E., Schoofs L., Tytgat J.;
RT "Purification, characterization and biosynthesis of parabutoxin 3, a
RT component of Parabuthus transvaalicus venom.";
RL Eur. J. Biochem. 269:1854-1865(2002).
RN [2]
RP MUTAGENESIS OF ASN-24.
RX PubMed=12752777; DOI=10.1046/j.1460-9568.2003.02613.x;
RA Huys I., Tytgat J.;
RT "Evidence for a function-specific mutation in the neurotoxin, parabutoxin
RT 3.";
RL Eur. J. Neurosci. 17:1786-1792(2003).
RN [3]
RP ACTIVITY PROFILE.
RX PubMed=18687312; DOI=10.1016/j.bcp.2008.07.008;
RA Abdel-Mottaleb Y., Corzo G., Martin-Eauclaire M.F., Satake H., Ceard B.,
RA Peigneur S., Nambaru P., Bougis P.E., Possani L.D., Tytgat J.;
RT "A common 'hot spot' confers hERG blockade activity to alpha-scorpion
RT toxins affecting K+ channels.";
RL Biochem. Pharmacol. 76:805-815(2008).
CC -!- FUNCTION: Reversibly blocks voltage-gated potassium channels
CC (Kv1.1/KCNA1 (Kd=79 uM), Kv1.2/KCNA2 (Kd=547 nM) and Kv1.3/KCNA3
CC (Kd=492 nM)). {ECO:0000269|PubMed:11952787}.
CC -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:11952787}.
CC -!- TISSUE SPECIFICITY: Expressed by the venom gland. {ECO:0000305}.
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 -!- MISCELLANEOUS: Does not inhibit ERG1/Kv11.1/KCNH2 potassium channels.
CC {ECO:0000269|PubMed:18687312}.
CC -!- SIMILARITY: Belongs to the short scorpion toxin superfamily. Potassium
CC channel inhibitor family. Alpha-KTx 01 subfamily. {ECO:0000305}.
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DR AlphaFoldDB; P83112; -.
DR SMR; P83112; -.
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 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 1.10"
FT /evidence="ECO:0000269|PubMed:11952787"
FT /id="PRO_0000044917"
FT SITE 26
FT /note="Basic residue of the functional dyad"
FT /evidence="ECO:0000250"
FT SITE 35
FT /note="Aromatic residue of the functional dyad"
FT /evidence="ECO:0000250"
FT DISULFID 6..27
FT /evidence="ECO:0000250"
FT DISULFID 12..32
FT /evidence="ECO:0000250"
FT DISULFID 16..34
FT /evidence="ECO:0000250"
FT MUTAGEN 24
FT /note="N->F: 100-fold increase of affinity towards Kv1.1
FT channels, 5-fold increase in affinity towards Kv1.3
FT channels and no change in affinity towards Kv1.2 channels."
FT /evidence="ECO:0000269|PubMed:12752777"
SQ SEQUENCE 37 AA; 4280 MW; A4C9DF3AD856BE06 CRC64;
EVDMRCKSSK ECLVKCKQAT GRPNGKCMNR KCKCYPR
