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Protein

Alpha-conotoxin SrIA/SrIB

Gene
N/A
Organism
Conus spurius (Alphabet cone)
Status
Reviewed-Annotation score: Annotation score: 5 out of 5-Experimental evidence at protein leveli

Functioni

Alpha-conotoxins act on postsynaptic membranes, they bind to the nicotinic acetylcholine receptors (nAChR) and thus inhibit them. Has weak blocking effects on muscle nAChR composed of alpha-1/beta-1/gamma/delta subunits and the central nervous system nAChR composed of alpha-4/beta-2 subunits. Does not detectably affect the peripheral nervous system nAChR composed of alpha-3/beta-4 subunits. Low toxin concentrations potentiate currents in muscle nAChR composed of alpha-1/beta-1/gamma/delta subunits and central nervous system nAChR composed of alpha-4/beta-2 subunits, but not the peripheral nervous system nAChR composed of alpha-3/beta-4 subunits.1 Publication

GO - Molecular functioni

  • acetylcholine receptor inhibitor activity Source: UniProtKB
  • toxin activity Source: UniProtKB-KW

GO - Biological processi

  • pathogenesis Source: UniProtKB

Keywordsi

Molecular functionAcetylcholine receptor inhibiting toxin, Ion channel impairing toxin, Neurotoxin, Postsynaptic neurotoxin, Toxin

Names & Taxonomyi

Protein namesi
Recommended name:
Alpha-conotoxin SrIA/SrIB
OrganismiConus spurius (Alphabet cone)
Taxonomic identifieri192919 [NCBI]
Taxonomic lineageiEukaryotaMetazoaLophotrochozoaMolluscaGastropodaCaenogastropodaHypsogastropodaNeogastropodaConoideaConidaeConus

Organism-specific databases

ConoServeri3751. SrIA/SrIB precursor.

Subcellular locationi

Extracellular region or secreted Cytosol Plasma membrane Cytoskeleton Lysosome Endosome Peroxisome ER Golgi apparatus Nucleus Mitochondrion Manual annotation Automatic computational assertionGraphics by Christian Stolte; Source: COMPARTMENTS

Keywords - Cellular componenti

Secreted

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Signal peptidei1 – 21Sequence analysisAdd BLAST21
PropeptideiPRO_000037270822 – 48Sequence analysis1 PublicationAdd BLAST27
PeptideiPRO_000037270949 – 66Alpha-conotoxin SrIA/SrIBAdd BLAST18

Amino acid modifications

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Disulfide bondi51 ↔ 571 Publication
Disulfide bondi52 ↔ 651 Publication
Modified residuei554-hydroxyproline; in form Sr1A and Sr1B1 Publication1
Modified residuei604-carboxyglutamate; in form Sr1A1 Publication1
Modified residuei634-carboxyglutamate; in form Sr1A and Sr1B1 Publication1
Modified residuei66Glycine amide; in form Sr1A and Sr1B1 Publication1

Post-translational modificationi

Occurs in 2 forms which differ in the post-translational modification of Glu-60. In form SrA1 Glu-60 is 4-carboxyglutamate while in form SrA2 Glu-60 is unmodified.1 Publication

Keywords - PTMi

Amidation, Disulfide bond, Gamma-carboxyglutamic acid, Hydroxylation

Expressioni

Tissue specificityi

Expressed by the venom duct.1 Publication

Structurei

3D structure databases

ProteinModelPortaliP85886.
ModBaseiSearch...
MobiDBiSearch...

Family & Domainsi

Domaini

The cysteine framework is I (CC-C-C). Alpha4/7 pattern.

Sequence similaritiesi

Belongs to the conotoxin A superfamily.Curated

Keywords - Domaini

Signal

Family and domain databases

InterProiView protein in InterPro
IPR009958. Conotoxin_a-typ.
IPR018072. Conotoxin_a-typ_CS.
PfamiView protein in Pfam
PF07365. Toxin_8. 1 hit.
PROSITEiView protein in PROSITE
PS60014. ALPHA_CONOTOXIN. 1 hit.

Sequencei

Sequence statusi: Complete.

Sequence processingi: The displayed sequence is further processed into a mature form.

P85886-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
MGMRMMFTVF LLVVLATTVV SFTSDSAFDS RNVAANDKVS DMIALTARRT
60
CCSRPTCRME YPELCGGRR
Length:69
Mass (Da):7,689
Last modified:May 5, 2009 - v1
Checksum:i5124A4B09A970576
GO

Mass spectrometryi

Molecular mass is 2202.9 Da from positions 49 - 66. Determined by ESI. The measured mass is that of conotoxin Sr1A.1 Publication
Molecular mass is 2158.8 Da from positions 49 - 66. Determined by ESI. The measured mass is that of conotoxin Sr1B.1 Publication

Similar proteinsi

Entry informationi

Entry nameiCA1AB_CONSP
AccessioniPrimary (citable) accession number: P85886
Entry historyiIntegrated into UniProtKB/Swiss-Prot: May 5, 2009
Last sequence update: May 5, 2009
Last modified: November 22, 2017
This is version 19 of the entry and version 1 of the sequence. See complete history.
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programAnimal Toxin Annotation Program

Miscellaneousi

Keywords - Technical termi

Direct protein sequencing

Documents

  1. SIMILARITY comments
    Index of protein domains and families