CM3A_CONBU
ID CM3A_CONBU Reviewed; 77 AA.
AC C1J5M5;
DT 22-SEP-2009, integrated into UniProtKB/Swiss-Prot.
DT 26-MAY-2009, sequence version 1.
DT 25-MAY-2022, entry version 32.
DE RecName: Full=Mu-conotoxin BuIIIA {ECO:0000303|PubMed:18950653};
DE Flags: Precursor;
OS Conus bullatus (Bubble cone).
OC Eukaryota; Metazoa; Spiralia; Lophotrochozoa; Mollusca; Gastropoda;
OC Caenogastropoda; Neogastropoda; Conoidea; Conidae; Conus; Textilia.
OX NCBI_TaxID=89438;
RN [1]
RP NUCLEOTIDE SEQUENCE [MRNA], SYNTHESIS OF 52-74, FUNCTION ON NAV1.4/SCN4A,
RP AND AMIDATION AT CYS-74.
RC TISSUE=Venom duct;
RX PubMed=18950653; DOI=10.1016/j.toxicon.2008.10.017;
RA Holford M., Zhang M.-M., Gowd K.H., Azam L., Green B.R., Watkins M.,
RA Ownby J.-P., Yoshikami D., Bulaj G., Olivera B.M.;
RT "Pruning nature: biodiversity-derived discovery of novel sodium channel
RT blocking conotoxins from Conus bullatus.";
RL Toxicon 53:90-98(2009).
RN [2]
RP FUNCTION, AND SYNTHESIS OF 52-74.
RX PubMed=21652775; DOI=10.1073/pnas.1107027108;
RA Wilson M.J., Yoshikami D., Azam L., Gajewiak J., Olivera B.M., Bulaj G.,
RA Zhang M.M.;
RT "mu-Conotoxins that differentially block sodium channels Nav1.1 through 1.8
RT identify those responsible for action potentials in sciatic nerve.";
RL Proc. Natl. Acad. Sci. U.S.A. 108:10302-10307(2011).
CC -!- FUNCTION: Mu-conotoxins block voltage-gated sodium channels (Nav). This
CC synthetic toxin potently blocks rNav1.2/SCN2A, and rNav1.4/SCN4A. It
CC also moderately blocks rNav1.1/SCN1A, rNav1.3/SCN3A, rNav1.5/SCN5A, and
CC mNav1.6/SCN8A. The inhibition is reversible.
CC {ECO:0000269|PubMed:18950653, ECO:0000269|PubMed:21652775}.
CC -!- SUBCELLULAR LOCATION: Secreted {ECO:0000305|PubMed:18950653}.
CC -!- TISSUE SPECIFICITY: Expressed by the venom duct.
CC {ECO:0000305|PubMed:18950653}.
CC -!- DOMAIN: The cysteine framework is III (CC-C-C-CC). Classified in the M-
CC 5 branch, since 5 residues stand between the fourth and the fifth
CC cysteine residues. {ECO:0000305}.
CC -!- MISCELLANEOUS: Does not block rNav1.7/SCN9A, and rNav1.8/SCN10A.
CC {ECO:0000305|PubMed:21652775}.
CC -!- SIMILARITY: Belongs to the conotoxin M superfamily. {ECO:0000305}.
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DR EMBL; FJ240165; ACO50770.1; -; mRNA.
DR AlphaFoldDB; C1J5M5; -.
DR ConoServer; 3716; BuIIIA precursor.
DR GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR GO; GO:0008200; F:ion channel inhibitor activity; IEA:InterPro.
DR GO; GO:0017080; F:sodium channel regulator activity; IEA:UniProtKB-KW.
DR GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR InterPro; IPR004214; Conotoxin.
DR Pfam; PF02950; Conotoxin; 1.
PE 1: Evidence at protein level;
KW Amidation; Cleavage on pair of basic residues; Disulfide bond;
KW Ion channel impairing toxin; Neurotoxin; Secreted; Signal; Toxin;
KW Voltage-gated sodium channel impairing toxin.
FT SIGNAL 1..22
FT /evidence="ECO:0000255"
FT PROPEP 23..51
FT /evidence="ECO:0000305"
FT /id="PRO_0000384431"
FT PEPTIDE 52..74
FT /note="Mu-conotoxin BuIIIA"
FT /evidence="ECO:0000305|PubMed:18950653"
FT /id="PRO_0000384432"
FT REGION 26..46
FT /note="Disordered"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT COMPBIAS 28..46
FT /note="Basic and acidic residues"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT MOD_RES 74
FT /note="Cysteine amide"
FT /evidence="ECO:0000305|PubMed:18950653"
FT DISULFID 56..67
FT /evidence="ECO:0000250|UniProtKB:C1J5M6"
FT DISULFID 57..73
FT /evidence="ECO:0000250|UniProtKB:C1J5M6"
FT DISULFID 63..74
FT /evidence="ECO:0000250|UniProtKB:C1J5M6"
SQ SEQUENCE 77 AA; 8855 MW; C82F01747584D1F2 CRC64;
MMSKLGVLLT ICLLLFPLFA LPQDGDQPAD RPAERMQDDI SSEQNSLLEK RVTDRCCKGK
RECGRWCRDH SRCCGRR
