ID KAX52_ANDMA Reviewed; 31 AA. AC P31719; DT 01-JUL-1993, integrated into UniProtKB/Swiss-Prot. DT 01-JUL-1993, sequence version 1. DT 14-DEC-2022, entry version 97. DE RecName: Full=Potassium channel toxin alpha-KTx 5.2; DE AltName: Full=AmPO5; DE Short=P05 {ECO:0000303|PubMed:11527975, ECO:0000303|PubMed:8385026}; DE Short=PO5 {ECO:0000303|PubMed:11527975, ECO:0000303|PubMed:8385026}; DE AltName: Full=Leiurotoxin I-like toxin P05 {ECO:0000303|PubMed:8385026, ECO:0000303|PubMed:8457543}; OS Androctonus mauritanicus mauritanicus (Scorpion). OC Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida; OC Scorpiones; Buthida; Buthoidea; Buthidae; Androctonus. OX NCBI_TaxID=6860; RN [1] RP PROTEIN SEQUENCE, FUNCTION, AND SUBUNIT. RC TISSUE=Venom; RX PubMed=8385026; DOI=10.1016/0014-5793(93)80583-g; RA Zerrouk H., Mansuelle P., Benslimane A., Rochat H., Martin-Eauclaire M.-F.; RT "Characterization of a new leiurotoxin I-like scorpion toxin. PO5 from RT Androctonus mauretanicus mauretanicus."; RL FEBS Lett. 320:189-192(1993). RN [2] RP FUNCTION, AND SYNTHESIS. RX PubMed=8457543; DOI=10.1021/bi00062a005; RA Sabatier J.-M., Zerrouk H., Darbon H., Mabrouk K., Benslimane A., RA Rochat H., Martin-Eauclaire M.-F., van Rietschoten J.; RT "P05, a new leiurotoxin I-like scorpion toxin: synthesis and structure- RT activity relationships of the alpha-amidated analog, a ligand of Ca(2+)- RT activated K+ channels with increased affinity."; RL Biochemistry 32:2763-2770(1993). RN [3] RP FUNCTION, MUTAGENESIS OF THR-1; VAL-2; ARG-7 AND VAL-24, AND SITES ALA-1; RP PHE-6; ARG-7 AND VAL-24. RX PubMed=11527975; DOI=10.1074/jbc.m106981200; RA Shakkottai V.G., Regaya I., Wulff H., Fajloun Z., Tomita H., Fathallah M., RA Cahalan M.D., Gargus J.J., Sabatier J.M., Chandy K.G.; RT "Design and characterization of a highly selective peptide inhibitor of the RT small conductance calcium-activated K+ channel, SkCa2."; RL J. Biol. Chem. 276:43145-43151(2001). RN [4] RP STRUCTURE BY NMR, AND DISULFIDE BONDS. RX PubMed=8218272; DOI=10.1021/bi00096a005; RA Meunier S., Bernassau J.-M., Sabatier J.-M., Martin-Eauclaire M.-F., RA van Rietschoten J., Cambillau C., Darbon H.; RT "Solution structure of P05-NH2, a scorpion toxin analog with high affinity RT for the apamin-sensitive potassium channel."; RL Biochemistry 32:11969-11976(1993). CC -!- FUNCTION: Blocker for the small conductance calcium-activated potassium CC channels (PubMed:8385026, PubMed:8457543, PubMed:11527975). Shows CC similar affinities for KCa2.2/KCNN2 (Kd=22 nM) and KCa2.3/KCNN3 (Kd=25 CC nM) (PubMed:11527975). {ECO:0000269|PubMed:11527975, CC ECO:0000269|PubMed:8385026, ECO:0000269|PubMed:8457543}. CC -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:8385026}. CC -!- TISSUE SPECIFICITY: Expressed by the venom gland. CC {ECO:0000305|PubMed:8385026}. CC -!- DOMAIN: Has the structural arrangement of an alpha-helix connected to a CC beta-sheet by disulfide bonds (CSalpha/beta). CC {ECO:0000269|PubMed:8218272}. CC -!- SIMILARITY: Belongs to the short scorpion toxin superfamily. Potassium CC channel inhibitor family. Alpha-KTx 05 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 PIR; A49078; A49078. DR PDB; 1PNH; NMR; -; A=1-31. DR PDBsum; 1PNH; -. DR AlphaFoldDB; P31719; -. DR SMR; P31719; -. DR EvolutionaryTrace; P31719; -. 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 InterPro; IPR036574; Scorpion_toxin-like_sf. DR InterPro; IPR001947; Scorpion_toxinS_K_inh. DR Pfam; PF00451; Toxin_2; 1. DR SUPFAM; SSF57095; Scorpion toxin-like; 1. DR PROSITE; PS01138; SCORP_SHORT_TOXIN; 1. PE 1: Evidence at protein level; KW 3D-structure; Calcium-activated potassium channel impairing toxin; KW Direct protein sequencing; Disulfide bond; Ion channel impairing toxin; KW Neurotoxin; Potassium channel impairing toxin; Secreted; Toxin. FT PEPTIDE 1..31 FT /note="Potassium channel toxin alpha-KTx 5.2" FT /evidence="ECO:0000269|PubMed:8385026" FT /id="PRO_0000044928" FT REGION 6..9 FT /note="[R/K]XCQ motif" FT /evidence="ECO:0000305" FT SITE 1 FT /note="Interacts with KCa2.2/KCNN2 and KCa2.3/KCNN3" FT /evidence="ECO:0000305|PubMed:11527975" FT SITE 2 FT /note="Interacts with KCa2.2/KCNN2 and KCa2.3/KCNN3" FT /evidence="ECO:0000305|PubMed:11527975" FT SITE 7 FT /note="Interacts with KCa2.2/KCNN2 and KCa2.3/KCNN3" FT /evidence="ECO:0000305|PubMed:11527975" FT SITE 24 FT /note="Interacts with KCa2.2/KCNN2 and KCa2.3/KCNN3" FT /evidence="ECO:0000305|PubMed:11527975" FT DISULFID 3..21 FT /evidence="ECO:0000269|PubMed:8218272, FT ECO:0000312|PDB:1PNH" FT DISULFID 8..26 FT /evidence="ECO:0000269|PubMed:8218272, FT ECO:0000312|PDB:1PNH" FT DISULFID 12..28 FT /evidence="ECO:0000269|PubMed:8218272, FT ECO:0000312|PDB:1PNH" FT MUTAGEN 1 FT /note="T->A: 50-fold and 3-fold increase in potency of FT inhibition of KCa2.2/KCNN2 and KCa2.3/KCNN3, respectively." FT /evidence="ECO:0000269|PubMed:11527975" FT MUTAGEN 2 FT /note="V->F: 50-fold and 6-fold increase in potency of FT inhibition of KCa2.2/KCNN2 and KCa2.3/KCNN3, respectively." FT /evidence="ECO:0000269|PubMed:11527975" FT MUTAGEN 7 FT /note="R->M: 35-fold and 2-fold increase in potency of FT inhibition of KCa2.2/KCNN2 and KCa2.3/KCNN3, respectively." FT /evidence="ECO:0000269|PubMed:11527975" FT MUTAGEN 24 FT /note="V->D: No change in potency of inhibition of FT KCa2.2/KCNN2 and KCa2.3/KCNN3." FT /evidence="ECO:0000269|PubMed:11527975" FT HELIX 5..13 FT /evidence="ECO:0007829|PDB:1PNH" FT STRAND 16..22 FT /evidence="ECO:0007829|PDB:1PNH" FT STRAND 25..29 FT /evidence="ECO:0007829|PDB:1PNH" SQ SEQUENCE 31 AA; 3421 MW; 94B06CDC5CFB46FE CRC64; TVCNLRRCQL SCRSLGLLGK CIGVKCECVK H //