ID   TX21A_CTEON             Reviewed;          23 AA.
AC   P85270;
DT   11-SEP-2007, integrated into UniProtKB/Swiss-Prot.
DT   11-SEP-2007, sequence version 1.
DT   25-MAY-2022, entry version 30.
DE   RecName: Full=U3-ctenitoxin-Co1a {ECO:0000305};
DE            Short=U3-CNTX-Co1a {ECO:0000305};
DE   AltName: Full=Neurotoxin Oc F29-9 {ECO:0000303|Ref.1};
DE   Flags: Fragment;
OS   Ctenus ornatus (Brazilian spider) (Oligoctenus ornatus).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida; Araneae;
OC   Araneomorphae; Entelegynae; Lycosoidea; Ctenidae; Oligoctenus.
OX   NCBI_TaxID=406443;
RN   [1] {ECO:0000305}
RP   PROTEIN SEQUENCE, SUBCELLULAR LOCATION, AND MASS SPECTROMETRY.
RC   TISSUE=Venom;
RA   Borges M.H., Oliveira C.F.B., Goncalves J.M., Rates B., Santos D.M.,
RA   Pimenta A.M.C., Cordeiro M.N., Richardson M.;
RL   Submitted (JUL-2007) to UniProtKB.
CC   -!- FUNCTION: Antagonist of L-type calcium channels (Cav1/CACNA1).
CC       {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|Ref.1}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland. {ECO:0000305|Ref.1}.
CC   -!- DOMAIN: The presence of a 'disulfide through disulfide knot'
CC       structurally defines this protein as a knottin.
CC       {ECO:0000250|UniProtKB:P30288}.
CC   -!- MASS SPECTROMETRY: Mass=4685.8; Mass_error=0.13; Method=Electrospray;
CC       Evidence={ECO:0000269|Ref.1};
CC   -!- SIMILARITY: Belongs to the neurotoxin 02 (plectoxin) family. 01 (Tx3)
CC       subfamily. {ECO:0000255}.
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DR   AlphaFoldDB; P85270; -.
DR   ArachnoServer; AS000312; U3-ctenitoxin-Co1a.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0005246; F:calcium channel regulator activity; IEA:UniProtKB-KW.
DR   GO; GO:0008200; F:ion channel inhibitor activity; IEA:InterPro.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR   InterPro; IPR004169; Spidertoxin.
DR   Pfam; PF02819; Toxin_9; 1.
PE   1: Evidence at protein level;
KW   Calcium channel impairing toxin; Direct protein sequencing; Disulfide bond;
KW   Ion channel impairing toxin; Knottin; Neurotoxin; Secreted; Toxin;
KW   Voltage-gated calcium channel impairing toxin.
FT   CHAIN           1..>23
FT                   /note="U3-ctenitoxin-Co1a"
FT                   /id="PRO_0000302118"
FT   DISULFID        2..17
FT                   /evidence="ECO:0000250|UniProtKB:O76200"
FT   DISULFID        9..22
FT                   /evidence="ECO:0000250|UniProtKB:O76200"
FT   DISULFID        16..?
FT                   /evidence="ECO:0000250|UniProtKB:O76200"
FT   NON_TER         23
SQ   SEQUENCE   23 AA;  2629 MW;  A042ECBD7F8C31F3 CRC64;
     ACVPVYEECG TPKKRCCEER PCK