3S1EC_LATSE
ID 3S1EC_LATSE Reviewed; 83 AA.
AC Q7T2I5; P01435;
DT 21-JUL-1986, integrated into UniProtKB/Swiss-Prot.
DT 01-OCT-2003, sequence version 1.
DT 25-MAY-2022, entry version 78.
DE RecName: Full=Erabutoxin c {ECO:0000303|PubMed:4664580};
DE Short=ETXC;
DE Short=Ec {ECO:0000303|PubMed:4664580};
DE AltName: Full=Short neurotoxin 1c;
DE Flags: Precursor;
OS Laticauda semifasciata (Black-banded sea krait) (Pseudolaticauda
OS semifasciata).
OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Toxicofera;
OC Serpentes; Colubroidea; Elapidae; Laticaudinae; Laticauda.
OX NCBI_TaxID=8631;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC TISSUE=Liver;
RX PubMed=2249684; DOI=10.1111/j.1432-1033.1990.tb19380.x;
RA Fuse N., Tsuchiya T., Nonomura Y., Menez A., Tamiya T.;
RT "Structure of the snake short-chain neurotoxin, erabutoxin c, precursor
RT gene.";
RL Eur. J. Biochem. 193:629-633(1990).
RN [2]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC TISSUE=Liver;
RX PubMed=12957382; DOI=10.1016/s0378-1119(03)00637-1;
RA Fujimi T.J., Nakajyo T., Nishimura E., Ogura E., Tsuchiya T., Tamiya T.;
RT "Molecular evolution and diversification of snake toxin genes, revealed by
RT analysis of intron sequences.";
RL Gene 313:111-118(2003).
RN [3]
RP PROTEIN SEQUENCE OF 22-83, TOXIC DOSE, AND SUBCELLULAR LOCATION.
RX PubMed=4664580; DOI=10.1042/bj1300547;
RA Tamiya N., Abe H.;
RT "The isolation, properties and amino acid sequence of erabutoxin c, a minor
RT neurotoxic component of the venom of a sea snake Katicauda semifasciata.";
RL Biochem. J. 130:547-555(1972).
RN [4]
RP SEQUENCE REVISION.
RX PubMed=588261; DOI=10.1042/bj1670289;
RA Maeda N., Tamiya N.;
RT "Correction of partial amino acid sequence of erabutoxins.";
RL Biochem. J. 167:289-291(1977).
RN [5]
RP FUNCTION.
RX PubMed=7721859; DOI=10.1074/jbc.270.16.9362;
RA Tremeau O., Lemaire C., Drevet P., Pinkasfeld S., Ducancel F.,
RA Boulain J.-C., Menez A.;
RT "Genetic engineering of snake toxins. The functional site of Erabutoxin a,
RT as delineated by site-directed mutagenesis, includes variant residues.";
RL J. Biol. Chem. 270:9362-9369(1995).
CC -!- FUNCTION: Binds to muscle nicotinic acetylcholine receptor (nAChR) and
CC inhibit acetylcholine from binding to the receptor, thereby impairing
CC neuromuscular transmission. Binds to Torpedo marmorata nAChR (Kd=0.14
CC nM) (PubMed:7721859). {ECO:0000269|PubMed:7721859}.
CC -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:4664580}.
CC -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC {ECO:0000305|PubMed:4664580}.
CC -!- TOXIC DOSE: LD(50) is 0.15 mg/kg by intramuscular injection into mice.
CC {ECO:0000269|PubMed:4664580}.
CC -!- SIMILARITY: Belongs to the snake three-finger toxin family. Short-chain
CC subfamily. Type I alpha-neurotoxin sub-subfamily. {ECO:0000305}.
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DR EMBL; X51410; CAA35770.1; -; Genomic_DNA.
DR EMBL; AB098530; BAC78203.1; -; Genomic_DNA.
DR PIR; S14003; S14003.
DR PDB; 6PNW; X-ray; 2.00 A; A/B=22-83.
DR PDBsum; 6PNW; -.
DR AlphaFoldDB; Q7T2I5; -.
DR BMRB; Q7T2I5; -.
DR SMR; Q7T2I5; -.
DR GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
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 CDD; cd00206; snake_toxin; 1.
DR Gene3D; 2.10.60.10; -; 1.
DR InterPro; IPR003571; Snake_3FTx.
DR InterPro; IPR045860; Snake_toxin-like_sf.
DR InterPro; IPR018354; Snake_toxin_con_site.
DR SUPFAM; SSF57302; SSF57302; 1.
DR PROSITE; PS00272; SNAKE_TOXIN; 1.
PE 1: Evidence at protein level;
KW 3D-structure; Acetylcholine receptor inhibiting toxin;
KW Direct protein sequencing; Disulfide bond; Ion channel impairing toxin;
KW Neurotoxin; Postsynaptic neurotoxin; Secreted; Signal; Toxin.
FT SIGNAL 1..21
FT /evidence="ECO:0000269|PubMed:4664580"
FT CHAIN 22..83
FT /note="Erabutoxin c"
FT /evidence="ECO:0000269|PubMed:4664580"
FT /id="PRO_0000035448"
FT REGION 24..38
FT /note="Loop I"
FT /evidence="ECO:0000250|UniProtKB:P60775"
FT REGION 39..44
FT /note="Stretch between loop I and loop II"
FT /evidence="ECO:0000250|UniProtKB:P60775"
FT REGION 45..62
FT /note="Loop II"
FT /evidence="ECO:0000250|UniProtKB:P60775"
FT REGION 64..75
FT /note="Loop III"
FT /evidence="ECO:0000250|UniProtKB:P60775"
FT SITE 27
FT /note="Moderately important residue for binding to
FT acetylcholine receptor"
FT /evidence="ECO:0000250|UniProtKB:P60775"
FT SITE 28
FT /note="Very important residue for binding to acetylcholine
FT receptor"
FT /evidence="ECO:0000250|UniProtKB:P60775"
FT SITE 29
FT /note="Key residue for binding to acetylcholine receptor"
FT /evidence="ECO:0000250|UniProtKB:P60775"
FT SITE 30
FT /note="Moderately important residue for binding to
FT acetylcholine receptor"
FT /evidence="ECO:0000250|UniProtKB:P60775"
FT SITE 31
FT /note="Key residue for binding to acetylcholine receptor"
FT /evidence="ECO:0000250|UniProtKB:P60775"
FT SITE 46
FT /note="Moderately important residue for binding to
FT acetylcholine receptor"
FT /evidence="ECO:0000250|UniProtKB:P60775"
FT SITE 48
FT /note="Key residue for binding to acetylcholine receptor"
FT /evidence="ECO:0000250|UniProtKB:P60775"
FT SITE 50
FT /note="Very important residue for binding to acetylcholine
FT receptor"
FT /evidence="ECO:0000250|UniProtKB:P60775"
FT SITE 52
FT /note="Very important residue for binding to acetylcholine
FT receptor"
FT /evidence="ECO:0000250|UniProtKB:P60775"
FT SITE 53
FT /note="Moderately important residue for binding to
FT acetylcholine receptor"
FT /evidence="ECO:0000250|UniProtKB:P60775"
FT SITE 54
FT /note="Key residue for binding to acetylcholine receptor"
FT /evidence="ECO:0000250|UniProtKB:P60775"
FT SITE 55
FT /note="Moderately important residue for binding to
FT acetylcholine receptor"
FT /evidence="ECO:0000250|UniProtKB:P60775"
FT SITE 57
FT /note="Very important residue for binding to acetylcholine
FT receptor"
FT /evidence="ECO:0000250|UniProtKB:P60775"
FT SITE 59
FT /note="Very important residue for binding to acetylcholine
FT receptor"
FT /evidence="ECO:0000250|UniProtKB:P60775"
FT SITE 68
FT /note="Very important residue for binding to acetylcholine
FT receptor"
FT /evidence="ECO:0000250|UniProtKB:P60775"
FT DISULFID 24..45
FT /evidence="ECO:0007744|PDB:6PNW"
FT DISULFID 38..62
FT /evidence="ECO:0007744|PDB:6PNW"
FT DISULFID 64..75
FT /evidence="ECO:0007744|PDB:6PNW"
FT DISULFID 76..81
FT /evidence="ECO:0007744|PDB:6PNW"
FT STRAND 23..25
FT /evidence="ECO:0007829|PDB:6PNW"
FT STRAND 35..37
FT /evidence="ECO:0007829|PDB:6PNW"
FT STRAND 45..52
FT /evidence="ECO:0007829|PDB:6PNW"
FT STRAND 55..63
FT /evidence="ECO:0007829|PDB:6PNW"
FT STRAND 72..76
FT /evidence="ECO:0007829|PDB:6PNW"
SQ SEQUENCE 83 AA; 9146 MW; BBB499DE67BE50E4 CRC64;
MKTLLLTLVV VTIVCLDLGY TRICFNHQSS QPQTTKTCSP GESSCYHKQW SDFRGTIIER
GCGCPTVKPG INLSCCESEV CNN
