ID   O164_CONTE              Reviewed;          81 AA.
AC   Q9XZL1; Q9U646;
DT   29-AUG-2001, integrated into UniProtKB/Swiss-Prot.
DT   01-NOV-1999, sequence version 1.
DT   25-MAY-2022, entry version 72.
DE   RecName: Full=Omega-conotoxin-like TxO4;
DE   AltName: Full=Conotoxin TxMKLT1-0221;
DE   Contains:
DE     RecName: Full=Truncated TxO4 {ECO:0000305};
DE   Flags: Precursor;
OS   Conus textile (Cloth-of-gold cone).
OC   Eukaryota; Metazoa; Spiralia; Lophotrochozoa; Mollusca; Gastropoda;
OC   Caenogastropoda; Neogastropoda; Conoidea; Conidae; Conus; Cylinder.
OX   NCBI_TaxID=6494;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RC   TISSUE=Venom duct;
RX   PubMed=10573284; DOI=10.1016/s0196-9781(99)00116-3;
RA   Lu B.-S., Yu F., Zhao D., Huang P.-T., Huang C.-F.;
RT   "Conopeptides from Conus striatus and Conus textile by cDNA cloning.";
RL   Peptides 20:1139-1144(1999).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RX   PubMed=11158371; DOI=10.1093/oxfordjournals.molbev.a003786;
RA   Conticello S.G., Gilad Y., Avidan N., Ben-Asher E., Levy Z., Fainzilber M.;
RT   "Mechanisms for evolving hypervariability: the case of conopeptides.";
RL   Mol. Biol. Evol. 18:120-131(2001).
RN   [3]
RP   IDENTIFICATION BY MASS SPECTROMETRY, SUBCELLULAR LOCATION, HYDROXYLATION AT
RP   PRO-70, AND BROMINATION AT TRP-75.
RC   TISSUE=Venom;
RX   PubMed=22709442; DOI=10.1021/pr300312h;
RA   Bhatia S., Kil Y.J., Ueberheide B., Chait B.T., Tayo L., Cruz L., Lu B.,
RA   Yates J.R. III, Bern M.;
RT   "Constrained de novo sequencing of conotoxins.";
RL   J. Proteome Res. 11:4191-4200(2012).
CC   -!- FUNCTION: Omega-conotoxins act at presynaptic membranes, they bind and
CC       block voltage-gated calcium channels (Cav). {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:22709442}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom duct.
CC       {ECO:0000305|PubMed:22709442}.
CC   -!- DOMAIN: The presence of a 'disulfide through disulfide knot'
CC       structurally defines this protein as a knottin.
CC       {ECO:0000250|UniProtKB:Q26443}.
CC   -!- DOMAIN: The cysteine framework is VI/VII (C-C-CC-C-C). {ECO:0000305}.
CC   -!- PTM: TxO4 is found with and without hydroxyproline and these two forms
CC       have a bromotryptophan. Truncated TxO4 is found with and without
CC       bromotryptophan, and these two forms have no hydroxyproline.
CC       {ECO:0000269|PubMed:22709442}.
CC   -!- SIMILARITY: Belongs to the conotoxin O1 superfamily. {ECO:0000305}.
CC   ---------------------------------------------------------------------------
CC   Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms
CC   Distributed under the Creative Commons Attribution (CC BY 4.0) License
CC   ---------------------------------------------------------------------------
DR   EMBL; AF146357; AAD31917.1; -; mRNA.
DR   EMBL; AF193270; AAF07981.1; -; mRNA.
DR   AlphaFoldDB; Q9XZL1; -.
DR   SMR; Q9XZL1; -.
DR   ConoServer; 1103; TxO4 precursor.
DR   ConoServer; 871; TxO4 precursor.
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; IPR004214; Conotoxin.
DR   InterPro; IPR012321; Conotoxin_omega-typ_CS.
DR   Pfam; PF02950; Conotoxin; 1.
DR   PROSITE; PS60004; OMEGA_CONOTOXIN; 1.
PE   1: Evidence at protein level;
KW   Bromination; Calcium channel impairing toxin; Disulfide bond;
KW   Hydroxylation; Ion channel impairing toxin; Knottin; Neurotoxin;
KW   Presynaptic neurotoxin; Secreted; Signal; Toxin;
KW   Voltage-gated calcium channel impairing toxin.
FT   SIGNAL          1..22
FT                   /evidence="ECO:0000255"
FT   PROPEP          23..52
FT                   /evidence="ECO:0000250"
FT                   /id="PRO_0000034956"
FT   PEPTIDE         53..81
FT                   /note="Omega-conotoxin-like TxO4"
FT                   /evidence="ECO:0000269|PubMed:22709442"
FT                   /id="PRO_0000034957"
FT   PEPTIDE         65..81
FT                   /note="Truncated TxO4"
FT                   /evidence="ECO:0000305|PubMed:22709442"
FT                   /id="PRO_0000445112"
FT   MOD_RES         70
FT                   /note="4-hydroxyproline; partial"
FT                   /evidence="ECO:0000269|PubMed:22709442"
FT   MOD_RES         75
FT                   /note="6'-bromotryptophan; partial"
FT                   /evidence="ECO:0000269|PubMed:22709442"
FT   DISULFID        55..72
FT                   /evidence="ECO:0000250|UniProtKB:Q26443"
FT   DISULFID        62..76
FT                   /evidence="ECO:0000250|UniProtKB:Q26443"
FT   DISULFID        71..80
FT                   /evidence="ECO:0000250|UniProtKB:Q26443"
FT   CONFLICT        6..7
FT                   /note="VV -> MM (in Ref. 2; AAF07981)"
FT                   /evidence="ECO:0000305"
SQ   SEQUENCE   81 AA;  8959 MW;  4E76DC482930F536 CRC64;
     MKLTCVVIVA VLFLTAWTFV TAVPHSSNAL ENLYLKARHE MENPEASKLN TRYDCEPPGN
     FCGMIKIGPP CCSGWCFFAC A