ID   CA18_CONBE              Reviewed;          37 AA.
AC   A0A068B6Q6;
DT   16-OCT-2019, integrated into UniProtKB/Swiss-Prot.
DT   01-OCT-2014, sequence version 1.
DT   25-MAY-2022, entry version 31.
DE   RecName: Full=Conotoxin Bt1.8 {ECO:0000312|EMBL:AIC77077.1};
DE   Flags: Precursor; Fragment;
OS   Conus betulinus (Beech cone).
OC   Eukaryota; Metazoa; Spiralia; Lophotrochozoa; Mollusca; Gastropoda;
OC   Caenogastropoda; Neogastropoda; Conoidea; Conidae; Conus; Dendroconus.
OX   NCBI_TaxID=89764;
RN   [1] {ECO:0000312|EMBL:AIC77077.1}
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC   TISSUE=Venom gland;
RA   Zhang L.X., Liu Z.G., Dai Q.Y.;
RL   Submitted (JUL-2013) to the EMBL/GenBank/DDBJ databases.
RN   [2] {ECO:0007744|PDB:2NAY}
RP   STRUCTURE BY NMR OF 21-36, SYNTHESIS OF 21-36, AND DISULFIDE BONDS.
RA   Chenyun G., Biling H.;
RT   "The structure of the Bt1.8 peptide synthesized by solid-phase method.";
RL   Submitted (JAN-2016) to the PDB data bank.
CC   -!- FUNCTION: Alpha-conotoxins bind to the nicotinic acetylcholine
CC       receptors (nAChR) and inhibit them. {ECO:0000250|UniProtKB:Q86RB2}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000305}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom duct. {ECO:0000305}.
CC   -!- DOMAIN: The cysteine framework is I (CC-C-C). Alpha4/7 pattern.
CC       {ECO:0000305}.
CC   -!- SIMILARITY: Belongs to the conotoxin A superfamily. {ECO:0000305}.
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DR   EMBL; KF414094; AIC77077.1; -; Genomic_DNA.
DR   PDB; 2NAY; NMR; -; A=21-36.
DR   PDBsum; 2NAY; -.
DR   AlphaFoldDB; A0A068B6Q6; -.
DR   BMRB; A0A068B6Q6; -.
DR   SMR; A0A068B6Q6; -.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0035792; C:host cell postsynaptic membrane; IEA:UniProtKB-KW.
DR   GO; GO:0030550; F:acetylcholine receptor inhibitor activity; IEA:UniProtKB-KW.
DR   GO; GO:0099106; F:ion channel regulator activity; IEA:UniProtKB-KW.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR   InterPro; IPR009958; Conotoxin_a-typ.
DR   Pfam; PF07365; Toxin_8; 1.
PE   1: Evidence at protein level;
KW   3D-structure; Acetylcholine receptor inhibiting toxin; Amidation;
KW   Cleavage on pair of basic residues; Disulfide bond;
KW   Ion channel impairing toxin; Neurotoxin; Postsynaptic neurotoxin; Secreted;
KW   Toxin.
FT   PROPEP          <1..20
FT                   /evidence="ECO:0000250|UniProtKB:Q86RB2"
FT                   /id="PRO_0000448284"
FT   PEPTIDE         21..36
FT                   /note="Conotoxin Bt1.8"
FT                   /evidence="ECO:0000250|UniProtKB:Q86RB2"
FT                   /id="PRO_0000448285"
FT   MOD_RES         36
FT                   /note="Cysteine amide"
FT                   /evidence="ECO:0000250|UniProtKB:Q86RB2"
FT   DISULFID        22..28
FT                   /evidence="ECO:0007744|PDB:2NAY"
FT   DISULFID        23..36
FT                   /evidence="ECO:0007744|PDB:2NAY"
FT   NON_TER         1
FT                   /evidence="ECO:0000303|Ref.1"
FT   STRAND          23..26
FT                   /evidence="ECO:0007829|PDB:2NAY"
FT   HELIX           28..31
FT                   /evidence="ECO:0007829|PDB:2NAY"
SQ   SEQUENCE   37 AA;  3831 MW;  AD7B78FAC99863E5 CRC64;
     PDGRNAAAKA FDLITPTVRK GCCSNPACIL NNPNQCG