ID   TX9A_STIHA              Reviewed;          28 AA.
AC   P0C7W7;
DT   22-JUL-2008, integrated into UniProtKB/Swiss-Prot.
DT   22-JUL-2008, sequence version 1.
DT   23-FEB-2022, entry version 21.
DE   RecName: Full=Kappa-stichotoxin-Shd1a/kappa-stichotoxin-Shd1b {ECO:0000303|PubMed:22683676};
DE            Short=Kappa-SHTX-Shd1a/kappa-SHTX-Shd1b {ECO:0000303|PubMed:22683676};
DE   AltName: Full=Kappa-AnmTX Sha 9a-1 {ECO:0000303|PubMed:23801332};
DE   AltName: Full=Potassium channel toxin SHTX I/SHTX II {ECO:0000303|PubMed:18243416};
DE   AltName: Full=Potassium channel toxin SHTX-1/SHTX-2;
OS   Stichodactyla haddoni (Saddle carpet anemone) (Haddon's sea anemone).
OC   Eukaryota; Metazoa; Cnidaria; Anthozoa; Hexacorallia; Actiniaria;
OC   Stichodactylidae; Stichodactyla.
OX   NCBI_TaxID=475174;
RN   [1]
RP   PROTEIN SEQUENCE, FUNCTION, HYDROXYLATION AT PRO-6, TOXIC DOSE, AND
RP   DISULFIDE BONDS.
RX   PubMed=18243416; DOI=10.1016/j.peptides.2007.12.010;
RA   Honma T., Kawahata S., Ishida M., Nagai H., Nagashima Y., Shiomi K.;
RT   "Novel peptide toxins from the sea anemone Stichodactyla haddoni.";
RL   Peptides 29:536-544(2008).
RN   [2]
RP   NOMENCLATURE.
RX   PubMed=22683676; DOI=10.1016/j.toxicon.2012.05.020;
RA   Oliveira J.S., Fuentes-Silva D., King G.F.;
RT   "Development of a rational nomenclature for naming peptide and protein
RT   toxins from sea anemones.";
RL   Toxicon 60:539-550(2012).
RN   [3]
RP   NOMENCLATURE.
RX   PubMed=23801332; DOI=10.1074/jbc.m113.485516;
RA   Osmakov D.I., Kozlov S.A., Andreev Y.A., Koshelev S.G., Sanamyan N.P.,
RA   Sanamyan K.E., Dyachenko I.A., Bondarenko D.A., Murashev A.N., Mineev K.S.,
RA   Arseniev A.S., Grishin E.V.;
RT   "Sea anemone peptide with uncommon beta-hairpin structure inhibits acid-
RT   sensing ion channel 3 (ASIC3) and reveals analgesic activity.";
RL   J. Biol. Chem. 288:23116-23127(2013).
CC   -!- FUNCTION: Kappa-stichotoxin-Shd1a: inhibits voltage-gated potassium
CC       channels (Kv).
CC   -!- FUNCTION: Kappa-stichotoxin-Shd1b: inhibits voltage-gated potassium
CC       channels (Kv). This toxin inhibits the binding of 125I-alpha-
CC       dendrotoxin to synaptosomal membranes (IC(50)=270 nM).
CC       {ECO:0000269|PubMed:18243416}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000305}. Nematocyst {ECO:0000305}.
CC   -!- PTM: Occurs in 2 forms which differ in the post-translational
CC       modification of Pro-6. In form SHTX-1 (Shd1a) Pro-6 is a hydroxyproline
CC       while in form SHTX-2 (Shd1b) Pro-6 is unmodified.
CC   -!- TOXIC DOSE: PD(50) of SHTX-1 (Shd1a) and -2 (Shd1b) are 430 ug/kg into
CC       crabs. {ECO:0000269|PubMed:18243416}.
CC   -!- SIMILARITY: Belongs to the sea anemone structural class 9a family.
CC       {ECO:0000305|PubMed:23801332}.
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DR   TCDB; 8.B.15.1.1; the sea anemone peptide toxin class 4 (shtx) family.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0042151; C:nematocyst; IEA:UniProtKB-SubCell.
DR   GO; GO:0015459; F:potassium channel regulator activity; IEA:UniProtKB-KW.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
PE   1: Evidence at protein level;
KW   Direct protein sequencing; Disulfide bond; Hydroxylation;
KW   Ion channel impairing toxin; Nematocyst; Potassium channel impairing toxin;
KW   Secreted; Toxin; Voltage-gated potassium channel impairing toxin.
FT   PEPTIDE         1..28
FT                   /note="Kappa-stichotoxin-Shd1a/kappa-stichotoxin-Shd1b"
FT                   /evidence="ECO:0000269|PubMed:18243416"
FT                   /id="PRO_0000344519"
FT   MOD_RES         6
FT                   /note="4-hydroxyproline; in form SHTX-1 (Shd1a)"
FT                   /evidence="ECO:0000269|PubMed:18243416"
FT   DISULFID        7..19
FT                   /evidence="ECO:0000269|PubMed:18243416"
FT   DISULFID        10..25
FT                   /evidence="ECO:0000269|PubMed:18243416"
SQ   SEQUENCE   28 AA;  3065 MW;  F781718B1FC28F2A CRC64;
     XIIGAPCRRC YHSDGKGGCV RDWSCGQQ