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C1J5M6 (CM3B_CONBU) Reviewed, UniProtKB/Swiss-Prot

Last modified April 16, 2014. Version 23. Feed History...

Clusters with 100%, 90%, 50% identity | Documents (2) | Third-party data text xml rdf/xml gff fasta
to top of pageNames·Attributes·General annotation·Ontologies·Sequence annotation·Sequences·References·Web links·Cross-refs·Entry info·DocumentsCustomize order

Names and origin

Protein namesRecommended name:
Mu-conotoxin BuIIIB
Alternative name(s):
Conotoxin Bu16
OrganismConus bullatus (Bubble cone)
Taxonomic identifier89438 [NCBI]
Taxonomic lineageEukaryotaMetazoaLophotrochozoaMolluscaGastropodaCaenogastropodaHypsogastropodaNeogastropodaConoideaConidaeConus

Protein attributes

Sequence length78 AA.
Sequence statusComplete.
Sequence processingThe displayed sequence is further processed into a mature form.
Protein existenceEvidence at protein level

General annotation (Comments)

Function

Mu-conotoxins block voltage-gated sodium channels (Nav). This synthetic toxin potently blocks rNav1.2/SCN2A, and rNav1.4/SCN4A. It also moderately blocks rNav1.1/SCN1A, rNav1.3/SCN3A, rNav1.5/SCN5, and mNav1.6/SCN8A. The block of SCN4A is very slowly reversible. Ref.1 Ref.3 Ref.4

Subcellular location

Secreted By similarity.

Tissue specificity

Expressed by the venom duct.

Domain

The cysteine framework is III (CC-C-C-CC). Classified in the M-5 branch, since 5 residues stand between the fourth and the fifth cysteine residues.

Sequence similarities

Belongs to the conotoxin M superfamily.

Ontologies

Keywords
   Cellular componentSecreted
   DomainSignal
   Molecular functionIon channel impairing toxin
Neurotoxin
Toxin
Voltage-gated sodium channel impairing toxin
   PTMAmidation
Cleavage on pair of basic residues
Disulfide bond
   Technical term3D-structure
Gene Ontology (GO)
   Biological_processpathogenesis

Inferred from electronic annotation. Source: InterPro

   Cellular_componentextracellular region

Inferred from electronic annotation. Source: UniProtKB-SubCell

   Molecular_functionion channel inhibitor activity

Inferred from electronic annotation. Source: InterPro

Complete GO annotation...

Sequence annotation (Features)

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifier

Molecule processing

Signal peptide1 – 2222 Potential
Propeptide23 – 5129 By similarity
PRO_0000384433
Peptide52 – 7524Mu-conotoxin BuIIIB
PRO_0000384434

Amino acid modifications

Modified residue751Cysteine amide By similarity
Disulfide bond56 ↔ 68 Ref.4
Disulfide bond57 ↔ 74 Ref.4
Disulfide bond64 ↔ 75 Ref.4

Experimental info

Mutagenesis52 – 554Missing: 4-fold increase in blocking SCN3A (K(d) is 53 nM). Ref.4
Mutagenesis521V → A: 3.5-decrease in blocking SCN3A (K(d) is 710 nM). Ref.4
Mutagenesis531G → A: 5-fold increase in blocking SCN3A (K(d) is 36 nM). Ref.4
Mutagenesis531G → A: Mutated into D-Ala. 40-fold increase in blocking SCN3A (K(d) is 4.8 nM). Ref.4
Mutagenesis541E → A: 13-fold increase in blocking SCN3A (K(d) is 15 nM). Ref.4
Mutagenesis551R → A: No change in blocking SCN3A (K(d) is 118 nM). Ref.4

Secondary structure

....... 78
Helix Strand Turn

Details...

Sequences

Sequence LengthMass (Da)Tools
C1J5M6 [UniParc].

Last modified May 26, 2009. Version 1.
Checksum: 907D09C9B4DE3164

FASTA788,877
        10         20         30         40         50         60 
MMSKLGVLLT ICLLLFPLFA LPQDGDQPAD RPAERMQDDI SSEQNPLLEK RVGERCCKNG 

        70 
KRGCGRWCRD HSRCCGRR 

« Hide

References

[1]"Pruning nature: biodiversity-derived discovery of novel sodium channel blocking conotoxins from Conus bullatus."
Holford M., Zhang M.-M., Gowd K.H., Azam L., Green B.R., Watkins M., Ownby J.-P., Yoshikami D., Bulaj G., Olivera B.M.
Toxicon 53:90-98(2009) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [MRNA], SYNTHESIS OF 51-75, FUNCTION ON SCN4A.
[2]"Characterization of the Conus bullatus genome and its venom-duct transcriptome."
Hu H., Bandyopadhyay P.K., Olivera B.M., Yandell M.
BMC Genomics 12:60-60(2011) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [MRNA] OF 26-78.
Tissue: Venom duct.
[3]"mu-Conotoxins that differentially block sodium channels Nav1.1 through 1.8 identify those responsible for action potentials in sciatic nerve."
Wilson M.J., Yoshikami D., Azam L., Gajewiak J., Olivera B.M., Bulaj G., Zhang M.M.
Proc. Natl. Acad. Sci. U.S.A. 108:10302-10307(2011) [PubMed] [Europe PMC] [Abstract]
Cited for: FUNCTION ON SODIUM CHANNELS, SYNTHESIS OF 52-75.
[4]"Mammalian neuronal sodium channel blocker mu-conotoxin BuIIIB has a structured N-terminus that influences potency."
Kuang Z., Zhang M.-M., Gupta K., Gajewiak J., Gulyas J., Balaram P., Rivier J.E., Olivera B.M., Yoshikami D., Bulaj G., Norton R.S.
ACS Chem. Biol. 8:1344-1351(2013) [PubMed] [Europe PMC] [Abstract]
Cited for: STRUCTURE BY NMR OF 52-75, SYNTHESIS OF 52-75, MUTAGENESIS OF VAL-52; GLY-53; GLU-54; ARG-55 AND 52-VAL--ARG-55, FUNCTION ON SCN3A, DISULFIDE BONDS.

Web resources

Biological Magnetic Resonance Data Bank

synthetic mu-BuIIIB

Biological Magnetic Resonance Data Bank

synthetic mutagen mu-[D-Ala2]BuIIIB

Cross-references

Sequence databases

EMBL
GenBank
DDBJ
FJ240166 mRNA. Translation: ACO50771.1.

3D structure databases

PDBe
RCSB-PDB
PDBj
EntryMethodResolution (Å)ChainPositionsPDBsum
2LO9NMR-A52-75[»]
2LOCNMR-A52-75[»]
ModBaseSearch...
MobiDBSearch...

Protocols and materials databases

StructuralBiologyKnowledgebaseSearch...

Organism-specific databases

ConoServer3715. BuIIIB precursor.

Family and domain databases

InterProIPR004214. Conotoxin.
[Graphical view]
PfamPF02950. Conotoxin. 1 hit.
[Graphical view]
ProtoNetSearch...

Entry information

Entry nameCM3B_CONBU
AccessionPrimary (citable) accession number: C1J5M6
Entry history
Integrated into UniProtKB/Swiss-Prot: September 22, 2009
Last sequence update: May 26, 2009
Last modified: April 16, 2014
This is version 23 of the entry and version 1 of the sequence. [Complete history]
Entry statusReviewed (UniProtKB/Swiss-Prot)
Annotation programAnimal Toxin Annotation Program

Relevant documents

SIMILARITY comments

Index of protein domains and families

PDB cross-references

Index of Protein Data Bank (PDB) cross-references