ID   JZT45_CHIGU             Reviewed;          83 AA.
AC   P0C5X7; B1P1B5;
DT   13-NOV-2007, integrated into UniProtKB/Swiss-Prot.
DT   05-OCT-2010, sequence version 2.
DT   25-MAY-2022, entry version 42.
DE   RecName: Full=Kappa-theraphotoxin-Cg2a;
DE            Short=Kappa-TRTX-Cg2a;
DE   AltName: Full=Jingzhaotoxin-12;
DE   AltName: Full=Jingzhaotoxin-45;
DE            Short=JZTX-45;
DE   AltName: Full=Jingzhaotoxin-XII;
DE            Short=JZTX-XII;
DE   AltName: Full=Peptide F4-20.99;
DE   Flags: Precursor;
OS   Chilobrachys guangxiensis (Chinese earth tiger tarantula) (Chilobrachys
OS   jingzhao).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida; Araneae;
OC   Mygalomorphae; Theraphosidae; Chilobrachys.
OX   NCBI_TaxID=278060;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA], TOXIN TARGET, AND FUNCTION.
RC   TISSUE=Venom gland;
RX   PubMed=18581053; DOI=10.1007/s00018-008-8135-x;
RA   Chen J., Deng M., He Q., Meng E., Jiang L., Liao Z., Rong M., Liang S.;
RT   "Molecular diversity and evolution of cystine knot toxins of the tarantula
RT   Chilobrachys jingzhao.";
RL   Cell. Mol. Life Sci. 65:2431-2444(2008).
RN   [2]
RP   PROTEIN SEQUENCE OF 54-82, AMIDATION AT LEU-82, AND IDENTIFICATION BY MASS
RP   SPECTROMETRY.
RC   TISSUE=Venom;
RX   PubMed=17476710; DOI=10.1002/pmic.200600785;
RA   Liao Z., Cao J., Li S., Yan X., Hu W., He Q., Chen J., Tang J., Xie J.,
RA   Liang S.;
RT   "Proteomic and peptidomic analysis of the venom from Chinese tarantula
RT   Chilobrachys jingzhao.";
RL   Proteomics 7:1892-1907(2007).
RN   [3]
RP   PROTEIN SEQUENCE OF 54-82, FUNCTION, MASS SPECTROMETRY, AND 3D-STRUCTURE
RP   MODELING.
RC   TISSUE=Venom;
RX   PubMed=17631373; DOI=10.1016/j.toxicon.2007.05.009;
RA   Yuan C., Liao Z., Zeng X., Dai L., Kuang F., Liang S.;
RT   "Jingzhaotoxin-XII, a gating modifier specific for Kv4.1 channels.";
RL   Toxicon 50:646-652(2007).
CC   -!- FUNCTION: Inhibits voltage-gated potassium channels of the subtype
CC       Kv4.1/KCND1 with high affinity and shows weak effects on Kv4.2/KCND2
CC       and Kv2.1/KCNB1 subtypes. The toxin modifies the gating behavior of the
CC       channel and may interact with the S3-S4 extracellular loop.
CC       {ECO:0000269|PubMed:17631373, ECO:0000269|PubMed:18581053}.
CC   -!- SUBCELLULAR LOCATION: Secreted.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC   -!- DOMAIN: The presence of a 'disulfide through disulfide knot'
CC       structurally defines this protein as a knottin. {ECO:0000250}.
CC   -!- MASS SPECTROMETRY: Mass=3665.4; Method=MALDI;
CC       Evidence={ECO:0000269|PubMed:17631373};
CC   -!- MISCELLANEOUS: This toxin does not inhibit Kv1.1/KCNA1, Kv1.2/KCNA2,
CC       Kv1.3/KCNA3, Kv1.4/KCNA4 and Kv3.1/KCNC1 potassium channels.
CC       {ECO:0000305|PubMed:17631373}.
CC   -!- SIMILARITY: Belongs to the neurotoxin 30 (phrixotoxin) family.
CC       {ECO:0000305}.
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DR   EMBL; EU233846; ABY71665.1; -; mRNA.
DR   AlphaFoldDB; P0C5X7; -.
DR   SMR; P0C5X7; -.
DR   ArachnoServer; AS000044; kappa-theraphotoxin-Cg2a.
DR   GO; GO:0005576; C:extracellular region; 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   Amidation; Direct protein sequencing; Disulfide bond;
KW   Ion channel impairing toxin; Knottin; Neurotoxin;
KW   Potassium channel impairing toxin; Secreted; Signal; Toxin;
KW   Voltage-gated potassium channel impairing toxin.
FT   SIGNAL          1..21
FT                   /evidence="ECO:0000255"
FT   PROPEP          22..53
FT                   /evidence="ECO:0000269|PubMed:17476710,
FT                   ECO:0000269|PubMed:17631373"
FT                   /id="PRO_0000398386"
FT   PEPTIDE         54..82
FT                   /note="Kappa-theraphotoxin-Cg2a"
FT                   /id="PRO_0000311605"
FT   MOD_RES         82
FT                   /note="Leucine amide"
FT                   /evidence="ECO:0000269|PubMed:17476710"
FT   DISULFID        55..69
FT                   /evidence="ECO:0000250"
FT   DISULFID        62..74
FT                   /evidence="ECO:0000250"
FT   DISULFID        68..78
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   83 AA;  9610 MW;  13E44BE244C84BDD CRC64;
     MKGSAFAIIL GLVVLCACSF AEDEQDQFAS PNELLRSMFL ESRHELIPEV EGRYCQKWMW
     TCDSERKCCE GYVCELWCKY NLG