ID   NA22_HETMG              Reviewed;          48 AA.
AC   P01534;
DT   21-JUL-1986, integrated into UniProtKB/Swiss-Prot.
DT   01-JAN-1988, sequence version 1.
DT   25-MAY-2022, entry version 87.
DE   RecName: Full=Delta-stichotoxin-Rpa1a {ECO:0000303|PubMed:22683676};
DE            Short=Delta-SHTX-Rpa1a {ECO:0000303|PubMed:22683676};
DE   AltName: Full=RpII {ECO:0000303|PubMed:2412579};
DE   AltName: Full=Toxin II {ECO:0000303|PubMed:2879552};
OS   Heteractis magnifica (Magnificent sea anemone) (Radianthus magnifica).
OC   Eukaryota; Metazoa; Cnidaria; Anthozoa; Hexacorallia; Actiniaria;
OC   Stichodactylidae; Heteractis.
OX   NCBI_TaxID=38281;
RN   [1]
RP   PROTEIN SEQUENCE, SUBCELLULAR LOCATION, FUNCTION, AND TOXIC DOSE.
RC   TISSUE=Nematoblast;
RX   PubMed=2412579; DOI=10.1021/bi00335a025;
RA   Schweitz H., Bidard J.-N., Frelin C., Pauron D., Vijverberg H.P.M.,
RA   Mahasneh D.M., Lazdunski M., Vilbois F., Tsugita A.;
RT   "Purification, sequence, and pharmacological properties of sea anemone
RT   toxins from Radianthus paumotensis. A new class of sea anemone toxins
RT   acting on the sodium channel.";
RL   Biochemistry 24:3554-3561(1985).
RN   [2]
RP   PROTEIN SEQUENCE, SUBCELLULAR LOCATION, STRUCTURE BY NMR, AND DISULFIDE
RP   BONDS.
RC   TISSUE=Nematoblast;
RX   PubMed=2879552; DOI=10.1021/bi00370a017;
RA   Wemmer D.E., Kumar N.V., Metrione R.M., Lazdunski M., Drobny G.,
RA   Kallenbach N.R.;
RT   "NMR analysis and sequence of toxin II from the sea anemone Radianthus
RT   paumotensis.";
RL   Biochemistry 25:6842-6849(1986).
RN   [3]
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).
CC   -!- FUNCTION: Binds specifically to voltage-gated sodium channels (Nav),
CC       thereby delaying their inactivation during signal transduction
CC       (PubMed:2412579). Its toxicity is weaker than that of RpIII (AC P08380)
CC       (PubMed:2412579). {ECO:0000269|PubMed:2412579}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:2412579,
CC       ECO:0000269|PubMed:2879552}. Nematocyst.
CC   -!- TOXIC DOSE: LD(50) is 4.2 mg/kg when intraperitoneally injected into
CC       mice. {ECO:0000269|PubMed:2412579}.
CC   -!- TOXIC DOSE: LD(50) is 12 ug/kg when intracutaneously injected into
CC       mice. {ECO:0000269|PubMed:2412579}.
CC   -!- TOXIC DOSE: LD(50) is 15 ug/kg when on crabs.
CC       {ECO:0000269|PubMed:2412579}.
CC   -!- SIMILARITY: Belongs to the sea anemone sodium channel inhibitory toxin
CC       family. Type II subfamily. {ECO:0000305}.
CC   -!- SEQUENCE CAUTION:
CC       Sequence=Ref.1; Type=Miscellaneous discrepancy; Note=Identical with that shown for positions 1-23 and differs considerably thereafter.; Evidence={ECO:0000305};
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DR   PIR; A90510; TZAZR2.
DR   AlphaFoldDB; P01534; -.
DR   BMRB; P01534; -.
DR   SMR; P01534; -.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0042151; C:nematocyst; IEA:UniProtKB-SubCell.
DR   GO; GO:0017080; F:sodium channel regulator activity; IEA:UniProtKB-KW.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR   GO; GO:0009966; P:regulation of signal transduction; IEA:InterPro.
DR   Gene3D; 2.20.20.10; -; 1.
DR   InterPro; IPR000693; Anenome_toxin.
DR   InterPro; IPR023355; Myo_ane_neurotoxin_sf.
DR   PIRSF; PIRSF001905; Anenome_toxin; 1.
PE   1: Evidence at protein level;
KW   Direct protein sequencing; Disulfide bond; Ion channel impairing toxin;
KW   Nematocyst; Neurotoxin; Secreted; Toxin;
KW   Voltage-gated sodium channel impairing toxin.
FT   CHAIN           1..48
FT                   /note="Delta-stichotoxin-Rpa1a"
FT                   /evidence="ECO:0000269|PubMed:2412579,
FT                   ECO:0000269|PubMed:2879552"
FT                   /id="PRO_0000221527"
FT   DISULFID        3..43
FT                   /evidence="ECO:0000269|PubMed:2879552"
FT   DISULFID        5..33
FT                   /evidence="ECO:0000269|PubMed:2879552"
FT   DISULFID        26..44
FT                   /evidence="ECO:0000269|PubMed:2879552"
SQ   SEQUENCE   48 AA;  5295 MW;  B35C790E8BF4D677 CRC64;
     ASCKCDDDGP DVRSATFTGT VDFWNCNEGW EKCTAVYTPV ASCCRKKK