P45629 (KAX23_CENLL) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names	Recommended name: Potassium channel toxin alpha-KTx 2.3 Alternative name(s): CllTx1 Toxin I Toxin II.10.9.1 Toxin-1
Organism	Centruroides limpidus limpidus (Mexican scorpion)
Taxonomic identifier	29941 [NCBI]
Taxonomic lineage	Eukaryota › Metazoa › Arthropoda › Chelicerata › Arachnida › Scorpiones › Buthida › Buthoidea › Buthidae › Centruroides

Protein attributes

Sequence length	38 AA.
Sequence status	Complete.
Protein existence	Evidence at protein level

General annotation (Comments)

Function	Blocks selectively the high conductance calcium-activated (maxi-K) potassium channels.
Subcellular location	Secreted.
Tissue specificity	Expressed by the venom gland.
Sequence similarities	Belongs to the short scorpion toxin superfamily. Potassium channel inhibitor family. Alpha-KTx 2 subfamily.

Ontologies

Keywords
Cellular component	Secreted
Molecular function	Ionic channel inhibitor Neurotoxin Potassium channel inhibitor Toxin
PTM	Disulfide bond
Technical term	Direct protein sequencing
Gene Ontology (GO)
Biological process	pathogenesis Inferred from electronic annotation. Source: InterPro
Cellular component	extracellular region Inferred from electronic annotation. Source: UniProtKB-SubCell
Molecular function	potassium 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
	Peptide	1 – 38	38	Potassium channel toxin alpha-KTx 2.3		PRO_0000044902
Regions
	Region	26 – 34	9	Interaction with Ca(2+)-activated K(+) channels Potential
Sites
	Site	28	1	Basic residue of the functional dyad By similarity
	Site	37	1	Aromatic residue of the functional dyad By similarity
Amino acid modifications
	Disulfide bond	7 ↔ 29		By similarity
	Disulfide bond	13 ↔ 34		By similarity
	Disulfide bond	17 ↔ 36		By similarity

Sequences

	Sequence		Length	Mass (Da)
	P45629 [UniParc]. Last modified November 1, 1995. Version 1. Checksum: 8B7E33F71D4AF009	FASTA	38	4,197
	10 20 30 ITINVKCTSP QQCLRPCKDR FGQHAGGKCI NGKCKCYP

References

[1]	"Novel K(+)-channel-blocking toxins from the venom of the scorpion Centruroides limpidus limpidus Karsch." Martin B.M., Ramirez A.N., Gurrola G.B., Nobile M., Prestipino G., Possani L.D. Biochem. J. 304:51-56(1994) [PubMed: 7998956] [Abstract] Cited for: PROTEIN SEQUENCE. Tissue: Venom.
+	Additional computationally mapped references.

Cross-references

Sequence databases
PIR	S53330.
3D structure databases
ProteinModelPortal	P45629.
SMR	P45629. Positions 2-38.
ModBase	Search...
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Family and domain databases
InterPro	IPR001947. Scorpion_toxinS. [Graphical view]
Pfam	PF00451. Toxin_2. 1 hit. [Graphical view]
PRINTS	PR00286. CHARYBDTOXIN.
ProDom	PD003586. Scorpion_toxinS. 1 hit. [Graphical view] [Entries sharing at least one domain]
PROSITE	PS01138. SCORP_SHORT_TOXIN. 1 hit. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

KAX23_CENLL

Accession

Primary (citable) accession number: P45629

Entry history

Integrated into UniProtKB/Swiss-Prot:	November 1, 1995
Last sequence update:	November 1, 1995
Last modified:	November 16, 2011
This is version 56 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Animal Toxin Annotation Program