CA2B_CONER
ID CA2B_CONER Reviewed; 70 AA.
AC C0HKF6; A0A346CIS6;
DT 10-MAY-2017, integrated into UniProtKB/Swiss-Prot.
DT 10-FEB-2021, sequence version 2.
DT 25-MAY-2022, entry version 14.
DE RecName: Full=Alpha-conotoxin EIIB {ECO:0000303|PubMed:28238803};
DE AltName: Full=E1.2 {ECO:0000305};
DE Flags: Precursor;
OS Conus ermineus (Agate cone) (Chelyconus ermineus).
OC Eukaryota; Metazoa; Spiralia; Lophotrochozoa; Mollusca; Gastropoda;
OC Caenogastropoda; Neogastropoda; Conoidea; Conidae; Conus; Chelyconus.
OX NCBI_TaxID=55423;
RN [1]
RP NUCLEOTIDE SEQUENCE [MRNA].
RX PubMed=30060147; DOI=10.1093/gbe/evy150;
RA Abalde S., Tenorio M.J., Afonso C.M., Zardoya R.;
RT "Conotoxin diversity in Chelyconus ermineus (Born, 1778) and the convergent
RT origin of piscivory in the Atlantic and Indo-Pacific cones.";
RL Genome Biol. Evol. 10:2643-2662(2018).
RN [2] {ECO:0000305}
RP PROTEIN SEQUENCE OF 52-67, FUNCTION, SUBCELLULAR LOCATION, IDENTIFICATION
RP BY MASS SPECTROMETRY, PYROGLUTAMATE FORMATION AT GLN-52, HYDROXYLATION AT
RP PRO-54, AND AMIDATION AT CYS-67.
RC TISSUE=Venom {ECO:0000303|PubMed:28238803};
RX PubMed=28238803; DOI=10.1016/j.toxicon.2017.02.023;
RA Echterbille J., Gilles N., Araoz R., Mourier G., Amar M., Servent D.,
RA De Pauw E., Quinton L.;
RT "Discovery and characterization of EIIB, a new alpha-conotoxin from Conus
RT ermineus venom by nAChRs affinity capture monitored by MALDI-TOF/TOF mass
RT spectrometry.";
RL Toxicon 130:1-10(2017).
CC -!- FUNCTION: Alpha-conotoxins bind to the nicotinic acetylcholine
CC receptors (nAChR) and inhibit them. This peptide potently blocks
CC muscular nicotinic acetylcholine receptor (CHRNA1-CHRNB1-CHRNG-CHRND),
CC and has no effect on neuronal receptors. It is able to totally displace
CC [125I]-Bgtx from the Torpedo receptor with an inhibition constant (Ki)
CC of 2.2 and 0.7 nM. {ECO:0000269|PubMed:28238803}.
CC -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:28238803}.
CC -!- TISSUE SPECIFICITY: Expressed by the venom duct.
CC {ECO:0000305|PubMed:28238803}.
CC -!- MASS SPECTROMETRY: Mass=1753.704; Mass_error=0.1; Method=MALDI;
CC Evidence={ECO:0000269|PubMed:28238803};
CC -!- SIMILARITY: Belongs to the conotoxin A 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; MH360426; AXL95475.1; -; mRNA.
DR AlphaFoldDB; C0HKF6; -.
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: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 Acetylcholine receptor inhibiting toxin; Amidation;
KW Cleavage on pair of basic residues; Direct protein sequencing;
KW Disulfide bond; Hydroxylation; Neurotoxin; Postsynaptic neurotoxin;
KW Pyrrolidone carboxylic acid; Secreted; Signal; Toxin.
FT SIGNAL 1..21
FT /evidence="ECO:0000255"
FT PROPEP 22..51
FT /id="PRO_0000451772"
FT PEPTIDE 52..67
FT /note="Alpha-conotoxin EIIB"
FT /evidence="ECO:0000269|PubMed:28238803"
FT /id="PRO_0000439887"
FT MOD_RES 52
FT /note="Pyrrolidone carboxylic acid"
FT /evidence="ECO:0000269|PubMed:28238803"
FT MOD_RES 54
FT /note="Hydroxyproline"
FT /evidence="ECO:0000269|PubMed:28238803"
FT MOD_RES 67
FT /note="Cysteine amide"
FT /evidence="ECO:0000269|PubMed:28238803"
FT DISULFID 56..62
FT /evidence="ECO:0000250|UniProtKB:P50982"
FT DISULFID 57..67
FT /evidence="ECO:0000250|UniProtKB:P50982"
SQ SEQUENCE 70 AA; 7775 MW; B43D6635E7157C8B CRC64;
MGMRMMFIVF LLVVLATTVV SFTLDHVLGL ASEGRNAKAI DNALDQRDPK RQTPGCCWHP
ACGKNRCGRR
