P15471 (CAS1_CONST) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names	Recommended name: Alpha-conotoxin S1 Alternative name(s): SI
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	64 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	Alpha-conotoxins act on postsynaptic membranes, they bind to the nicotinic acetylcholine receptors (nAChR) and thus inhibit them. This toxin blocks muscular nAChRs alpha-1/gamma and alpha-1/delta subunits.
Subcellular location	Secreted.
Tissue specificity	Expressed by the venom duct.
Domain	The cysteine framework is I (CC-C-C).
Sequence similarities	Belongs to the conotoxin A superfamily.

Ontologies

Keywords
Cellular component	Secreted
Domain	Signal
Molecular function	Acetylcholine receptor inhibiting toxin Neurotoxin Postsynaptic neurotoxin Toxin
PTM	Amidation Disulfide bond
Technical term	3D-structure Direct protein sequencing
Gene Ontology (GO)
Biological_process	pathogenesis Inferred from electronic annotation. Source: InterPro
Cellular_component	other organism postsynaptic membrane Inferred from electronic annotation. Source: UniProtKB-KW
Molecular_function	acetylcholine receptor inhibitor activity Inferred from electronic annotation. Source: InterPro
Complete GO annotation...

Sequence annotation (Features)

Feature key

Position(s)

Length

Description

Graphical view

Feature identifier

Molecule processing

Signal peptide

1 – 21

21

Potential

Propeptide

22 – 49

28

PRO_0000034887

Peptide

50 – 62

13

Alpha-conotoxin S1 Ref.3

PRO_0000034888

Amino acid modifications

Modified residue

62

1

Cysteine amide Ref.4

Disulfide bond

51 ↔ 56

Ref.4

Disulfide bond

52 ↔ 62

Ref.4

Secondary structure

1

.

.

.

64

Helix Strand Turn

Details...

Helix

54 – 59

6

Sequences

	Sequence		Length	Mass (Da)
	P15471 [UniParc]. Last modified July 11, 2002. Version 2. Checksum: B104B80CCD7C3B41	FASTA	64	7,164
	10 20 30 40 50 60 MGMRMMFTVF LLVVLATTVV SFPSDRASDG RDDEAKDERS DMHESDRKEI CCNPACGPKY SCGR

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]	"The A-superfamily of conotoxins: structural and functional divergence." Santos A.D., McIntosh J.M., Hillyard D.R., Cruz L.J., Olivera B.M. J. Biol. Chem. 279:17596-17606(2004) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA]. Tissue: Venom duct.
[3]	"Phylogenetic specificity of cholinergic ligands: alpha-conotoxin SI." Zafaralla G.C., Ramilo C., Gray W.R., Karlstroem R., Olivera B.M., Cruz L.J. Biochemistry 27:7102-7105(1988) [PubMed] [Europe PMC] [Abstract] Cited for: PROTEIN SEQUENCE OF 50-62. Tissue: Venom.
[4]	"Solution structure of alpha-conotoxin SI." Benie A.J., Whitford D., Hargittai B., Barany G., Janes R.W. FEBS Lett. 476:287-295(2000) [PubMed] [Europe PMC] [Abstract] Cited for: STRUCTURE BY NMR OF 50-62, DISULFIDE BONDS, AMIDATION AT CYS-62.

Cross-references

Sequence databases

PIR

A28953.

3D structure databases

PDBe
RCSB PDB
PDBj

Entry	Method	Resolution (Å)	Chain	Positions	PDBsum
1HJE	X-ray	0.75	A	50-62	[»]
1QMW	NMR	-	A	50-62	[»]

ProteinModelPortal

P15471.

ModBase

Search...

Protocols and materials databases

StructuralBiologyKnowledgebase

Search...

Organism-specific databases

ConoServer

76. SI precursor.

Family and domain databases

InterPro

IPR009958. Conotoxin_a-typ.
IPR018072. Conotoxin_a-typ_CS.
[Graphical view]

Pfam

PF07365. Toxin_8. 1 hit.
[Graphical view]

PROSITE

PS60014. ALPHA_CONOTOXIN. 1 hit.
[Graphical view]

ProtoNet

Search...

Other

EvolutionaryTrace

P15471.

Entry information

Entry name

CAS1_CONST

Accession

Primary (citable) accession number: P15471

Entry history

Integrated into UniProtKB/Swiss-Prot:	April 1, 1990
Last sequence update:	July 11, 2002
Last modified:	May 29, 2013
This is version 70 of the entry and version 2 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Animal Toxin Annotation Program