ID   KGX31_CENNO             Reviewed;          43 AA.
AC   P59939;
DT   31-OCT-2003, integrated into UniProtKB/Swiss-Prot.
DT   31-OCT-2003, sequence version 1.
DT   25-MAY-2022, entry version 63.
DE   RecName: Full=Potassium channel toxin gamma-KTx 3.1 {ECO:0000303|PubMed:12459475};
DE   AltName: Full=CnErgTx2 {ECO:0000303|PubMed:11978818};
DE            Short=CnErg2 {ECO:0000303|PubMed:11978818};
DE   AltName: Full=Ergtoxin-2 {ECO:0000303|PubMed:11978818};
DE            Short=ErgTx2 {ECO:0000303|PubMed:11978818};
DE   AltName: Full=Ergtoxin-like protein {ECO:0000303|PubMed:12459475};
OS   Centruroides noxius (Mexican scorpion).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC   Scorpiones; Buthida; Buthoidea; Buthidae; Centruroides.
OX   NCBI_TaxID=6878;
RN   [1]
RP   PROTEIN SEQUENCE, SUBCELLULAR LOCATION, AND NOMENCLATURE.
RC   TISSUE=Venom;
RX   PubMed=12459475; DOI=10.1016/s0014-5793(02)03652-9;
RA   Corona M., Gurrola G.B., Merino E., Cassulini R.R., Valdez-Cruz N.A.,
RA   Garcia B., Ramirez-Dominguez M.E., Coronas F.I., Zamudio F.Z., Wanke E.,
RA   Possani L.D.;
RT   "A large number of novel Ergtoxin-like genes and ERG K+-channels blocking
RT   peptides from scorpions of the genus Centruroides.";
RL   FEBS Lett. 532:121-126(2002).
RN   [2]
RP   PROTEIN SEQUENCE OF 1-3, FUNCTION, AND MASS SPECTROMETRY.
RC   TISSUE=Venom;
RX   PubMed=11978818; DOI=10.1523/jneurosci.22-09-03414.2002;
RA   Lecchi M., Redaelli E., Rosati B., Gurrola G.B., Florio T., Crociani O.,
RA   Curia G., Cassulini R.R., Masi A., Arcangeli A., Olivotto M., Schettini G.,
RA   Possani L.D., Wanke E.;
RT   "Isolation of a long-lasting eag-related gene-type K+ current in MMQ
RT   lactotrophs and its accommodating role during slow firing and prolactin
RT   release.";
RL   J. Neurosci. 22:3414-3425(2002).
CC   -!- FUNCTION: Blocks Kv11/ERG potassium channels (tested in MMQ lactotroph
CC       cells that contain the three ERG channels: rKv11.1/KCNH2/ERG1,
CC       rKv11.2/KCNH6/ERG2 and rKv11.3/KCNH7/ERG3). This toxin can be used to
CC       distinguish slow deactivating components (ERGS) from fast deactivating
CC       components (ERGF) currents, since it specifically blocks ERGS.
CC       {ECO:0000269|PubMed:11978818}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:12459475}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland. {ECO:0000305}.
CC   -!- DOMAIN: The presence of a 'disulfide through disulfide knot'
CC       structurally defines this protein as a knottin. {ECO:0000250}.
CC   -!- DOMAIN: Has the CSalpha/beta fold, which comprises one or two short
CC       alpha helices connected to anti-parallel beta-sheets stabilized by
CC       three or four disulfide bonds. {ECO:0000250|UniProtKB:Q86QT3}.
CC   -!- MASS SPECTROMETRY: Mass=4783; Method=Unknown;
CC       Evidence={ECO:0000269|PubMed:11978818};
CC   -!- SIMILARITY: Belongs to the ergtoxin family. Gamma-KTx 3 subfamily.
CC       {ECO:0000305}.
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DR   AlphaFoldDB; P59939; -.
DR   SMR; P59939; -.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0019870; F:potassium channel inhibitor activity; IEA:InterPro.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR   Gene3D; 3.30.30.10; -; 1.
DR   InterPro; IPR012622; Ergtoxin.
DR   InterPro; IPR036574; Scorpion_toxin-like_sf.
DR   Pfam; PF08086; Toxin_17; 1.
DR   SUPFAM; SSF57095; SSF57095; 1.
DR   PROSITE; PS60026; ERGTX; 1.
PE   1: Evidence at protein level;
KW   Direct protein sequencing; Disulfide bond; Ion channel impairing toxin;
KW   Knottin; Neurotoxin; Potassium channel impairing toxin; Secreted; Toxin;
KW   Voltage-gated potassium channel impairing toxin.
FT   CHAIN           1..43
FT                   /note="Potassium channel toxin gamma-KTx 3.1"
FT                   /evidence="ECO:0000269|PubMed:12459475"
FT                   /id="PRO_0000066840"
FT   DISULFID        5..23
FT                   /evidence="ECO:0000250|UniProtKB:Q86QT3"
FT   DISULFID        11..34
FT                   /evidence="ECO:0000250|UniProtKB:Q86QT3"
FT   DISULFID        20..39
FT                   /evidence="ECO:0000250|UniProtKB:Q86QT3"
FT   DISULFID        24..41
FT                   /evidence="ECO:0000250|UniProtKB:Q86QT3"
SQ   SEQUENCE   43 AA;  4791 MW;  76851224D563EBC1 CRC64;
     GRDSCVNKSR CAKYGYYSQC EVCCKKAGHK GGTCDFFKCK CKV