P63019 (SCX12_CENNO) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names	Recommended name: Alpha-toxin Cn12
Organism	Centruroides noxius (Mexican scorpion)
Taxonomic identifier	6878 [NCBI]
Taxonomic lineage	Eukaryota › Metazoa › Arthropoda › Chelicerata › Arachnida › Scorpiones › Buthida › Buthoidea › Buthidae › Centruroides

Protein attributes

Sequence length	67 AA.
Sequence status	Complete.
Protein existence	Evidence at protein level

General annotation (Comments)

Function	Alpha toxins bind voltage-independently at site-3 of sodium channels and inhibit the inactivation of the activated channels, thereby blocking neuronal transmission. This toxin binds, in vitro, to sodium channels and inhibits the inactivation of the activated channels. Seems not toxic to mice, crickets and sweet-water shrimps.
Subcellular location	Secreted.
Tissue specificity	Expressed by the venom gland.
Sequence similarities	Belongs to the long (4 C-C) scorpion toxin superfamily. Sodium channel inhibitor family. Beta subfamily.
Caution	This toxin sequence resembles the beta scorpion toxin class, although patch-clamp experiments shows the induction of supplementary slow inactivation of sodium channels, which means that it behaves like an alpha scorpion toxin.
Mass spectrometry	Molecular mass is 7139.5 Da from positions 1 - 67. Ref.1

Ontologies

Keywords
Cellular component	Secreted
Molecular function	Ionic channel inhibitor Neurotoxin Sodium channel inhibitor Toxin
PTM	Disulfide bond
Technical term	3D-structure Direct protein sequencing
Gene Ontology (GO)
Biological process	defense response Inferred from electronic annotation. Source: InterPro
Cellular component	extracellular region Inferred from electronic annotation. Source: UniProtKB-SubCell
Molecular function	sodium 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

Chain

1 – 67

67

Alpha-toxin Cn12

PRO_0000066772

Amino acid modifications

Disulfide bond

11 ↔ 65

Ref.1

Disulfide bond

15 ↔ 40

Ref.1

Disulfide bond

25 ↔ 45

Ref.1

Disulfide bond

29 ↔ 47

Ref.1

Secondary structure

1

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

67

Helix Strand Turn

Details...

Beta strand

8 – 10

3

Beta strand

12 – 14

3

Helix

25 – 31

7

Beta strand

41 – 44

4

Beta strand

46 – 49

4

Beta strand

51 – 53

3

Beta strand

63 – 65

3

Sequences

	Sequence		Length	Mass (Da)
	P63019 [UniParc]. Last modified August 31, 2004. Version 1. Checksum: B7BCAE8566FEC0EC	FASTA	67	7,148
	10 20 30 40 50 60 RDGYPLASNG CKFGCSGLGE NNPTCNHVCE KKAGSDYGYC YAWTCYCEHV AEGTVLWGDS GTGPCRS

References

[1]

"NMR solution structure of Cn12, a novel peptide from the Mexican scorpion Centruroides noxius with a typical beta-toxin sequence but with alpha-like physiological activity." del Rio-Portilla F., Hernandez-Marin E., Pimienta G., Coronas F.V., Zamudio F.Z., Rodriguez de la Vega R.C., Wanke E., Possani L.D. Eur. J. Biochem. 271:2504-2516(2004) [PubMed: 15182366] [Abstract] Cited for: PROTEIN SEQUENCE, MASS SPECTROMETRY, STRUCTURE BY NMR, DISULFIDE BONDS. Tissue: Venom.

Cross-references

3D structure databases

PDBe
RCSB PDB
PDBj

Entry	Method	Resolution (Å)	Chain	Positions	PDBsum
1PE4	NMR	-	A	1-67	[»]

ProteinModelPortal

P63019.

SMR

P63019. Positions 1-67.

ModBase

Search...

Protocols and materials databases

StructuralBiologyKnowledgebase

Search...

Family and domain databases

InterPro

IPR003614. Knot1.
IPR002061. Scorpion_toxin_lc.
[Graphical view]

Pfam

PF00537. Toxin_3. 1 hit.
[Graphical view]

SMART

SM00505. Knot1. 1 hit.
[Graphical view]

ProtoNet

Search...

Entry information

Entry name

SCX12_CENNO

Accession

Primary (citable) accession number: P63019

Entry history

Integrated into UniProtKB/Swiss-Prot:	August 31, 2004
Last sequence update:	August 31, 2004
Last modified:	November 16, 2011
This is version 39 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Animal Toxin Annotation Program