P28880 (CO16A_CONST) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names	Recommended name: Omega-conotoxin SVIA Alternative name(s): SNX-157
Organism	Conus striatus (Striated cone)
Taxonomic identifier	6493 [NCBI]
Taxonomic lineage	cellular organisms › Eukaryota › Opisthokonta › Metazoa › Eumetazoa › Bilateria › Protostomia › Lophotrochozoa › Mollusca › Gastropoda › Caenogastropoda › Hypsogastropoda › Neogastropoda › Conoidea › Conidae › Conus

Protein attributes

Sequence length	72 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is further processed into a mature form.
Protein existence	Evidence at protein level

General annotation (Comments)

Function	Omega-conotoxins act at presynaptic membranes, they bind and block voltage-gated calcium channels (Cav).
Subcellular location	Secreted.
Tissue specificity	Expressed by the venom duct.
Domain	The presence of a 'disulfide through disulfide knot' structurally defines this protein as a knottin. The cysteine framework is VI/VII (C-C-CC-C-C).
Sequence similarities	Belongs to the conotoxin O1 superfamily.
Caution	Thr-72 is not followed in the nucleotide sequence by the expected Gly residue required to produce amidation.

Ontologies

Keywords
Cellular component	Secreted
Domain	Knottin Signal
Molecular function	Calcium channel inhibitor Ion channel impairing toxin Neurotoxin Presynaptic neurotoxin Toxin
PTM	Amidation Disulfide bond Hydroxylation
Technical term	Direct protein sequencing
Gene Ontology (GO)
Biological_process	pathogenesis Inferred from electronic annotation. Source: InterPro
Cellular_component	other organism presynaptic membrane Inferred from electronic annotation. Source: UniProtKB-KW
Molecular_function	calcium channel inhibitor activity Inferred from electronic annotation. Source: UniProtKB-KW
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Signal peptide	1 – 22	22	Potential
	Propeptide	23 – 48	26			PRO_0000034924
	Peptide	49 – 72	24	Omega-conotoxin SVIA Ref.2		PRO_0000034925
Amino acid modifications
	Modified residue	55	1	4-hydroxyproline
	Modified residue	72	1	Threonine amide Ref.2
	Disulfide bond	49 ↔ 63
	Disulfide bond	56 ↔ 66
	Disulfide bond	62 ↔ 71
Natural variations
	Natural variant	51	1	S → P in SVIA-1, SVIA-2 and SVIA-5. Ref.3
	Natural variant	54	1	S → P in SVIA-4. Ref.3
	Natural variant	55	1	P → S in SVIA-3. Ref.3
	Natural variant	59	1	T → A in SVIA-5. Ref.3
	Natural variant	67	1	Y → S in SVIA-2 and SVIA-5. Ref.3

Sequences

	Sequence		Length	Mass (Da)
	P28880 [UniParc]. Last modified August 29, 2001. Version 2. Checksum: 4A6A412E450469A1	FASTA	72	7,830
	10 20 30 40 50 60 MKLTCVMIVA VLLLTACQLI TAEDSRGTQK HRTLRSTARR SKSESTTRCR SSGSPCGVTS 70 ICCGRCYRGK CT

References

[1]	"Conopeptides from Conus striatus and Conus textile by cDNA cloning." Lu B.-S., Yu F., Zhao D., Huang P.-T., Huang C.-F. Peptides 20:1139-1144(1999) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA]. Tissue: Venom duct.
[2]	"Novel alpha- and omega-conotoxins from Conus striatus venom." Ramilo C., Zafaralla G.C., Nadasdi L., Hammerland L.G., Yoshikami D., Gray W.R., Kristipati R., Ramachandran J., Miljanich G.P., Olivera B.M., Cruz L.J. Biochemistry 31:9919-9926(1992) [PubMed] [Europe PMC] [Abstract] Cited for: PROTEIN SEQUENCE OF 49-72, SYNTHESIS OF 49-72, AMIDATION AT THR-72. Tissue: Venom.
[3]	"Analysis of expressed sequence tags from the venom ducts of Conus striatus: focusing on the expression profile of conotoxins." Pi C., Liu Y., Peng C., Jiang X., Liu J., Xu B., Yu X., Yu Y., Jiang X., Wang L., Dong M., Chen S., Xu A.-L. Biochimie 88:131-140(2006) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA] OF 49-72, VARIANTS PRO-51; PRO-54; SER-55; ALA-59 AND SER-67. Tissue: Venom duct.

Cross-references

Sequence databases
EMBL GenBank DDBJ	AF146347 mRNA. Translation: AAD31907.1.
PIR	B44379.
3D structure databases
ModBase	Search...
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Organism-specific databases
ConoServer	863. SVIA precursor.
Family and domain databases
InterPro	IPR004214. Conotoxin. IPR012321. Conotoxin_omega-typ_CS. [Graphical view]
Pfam	PF02950. Conotoxin. 1 hit. [Graphical view]
PROSITE	PS60004. OMEGA_CONOTOXIN. 1 hit. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

CO16A_CONST

Accession

Primary (citable) accession number: P28880
Secondary accession number(s): Q9UB26

Entry history

Integrated into UniProtKB/Swiss-Prot:	December 1, 1992
Last sequence update:	August 29, 2001
Last modified:	April 3, 2013
This is version 68 of the entry and version 2 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Animal Toxin Annotation Program