Reviewed, UniProtKB/Swiss-Prot P0C165 (KAX2C_CENEL)

Names and origin

Protein names	Recommended name:     Potassium channel toxin alpha-KTx 2.12 Alternative name(s):     Toxin Ce5
Organism	Centruroides elegans (Bark scorpion)
Taxonomic identifier	217897 [NCBI]
Taxonomic lineage	Eukaryota › Metazoa › Arthropoda › Chelicerata › Arachnida › Scorpiones › Buthida › Buthoidea › Buthidae › Centruroides

Protein attributes

Sequence length	39 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is not processed.
Protein existence	Evidence at protein level.

General annotation (Comments)

Function	Weakly blocks Kv1.3 voltage-gated potassium channels.
Subunit structure	Monomer.
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.
Mass spectrometry	Molecular mass is 4255 Da from positions 1 - 39. Determined by ESI. Ref.1

Ontologies

Keywords
Cellular component	Secreted
Molecular function	Ionic channel inhibitor Neurotoxin Potassium channel inhibitor Toxin
PTM	Amidation Disulfide bond
Technical term	Direct protein sequencing
Gene Ontology (GO)
Biological process	pathogenesis Inferred from electronic annotation. Source: UniProtKB-KW
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
	Chain	1 – 39	39	Potassium channel toxin alpha-KTx 2.12		PRO_0000226962
Amino acid modifications
	Modified residue	39	1	Isoleucine amide
	Disulfide bond	7 ↔ 29		By similarity
	Disulfide bond	13 ↔ 34		By similarity
	Disulfide bond	17 ↔ 36		By similarity

Sequences

	Sequence		Length	Mass (Da)
	P0C165-1 [UniParc]. Last modified March 7, 2006. Version 1. Checksum: FD6E90AE39297E10	FASTA	39	4,262
	10 20 30 TIINVKCTSP KQCLPPCKEI YGRHAGAKCM NGKCHCSKI

References

[1]

"Novel alpha-KTx peptides from the venom of the scorpion Centruroides elegans selectively blockade Kv1.3 over IKCa1 K+ channels of T cells." Olamendi-Portugal T., Somodi S., Fernandez J.A., Zamudio F.Z., Becerril B., Varga Z., Panyi G., Gaspar R., Possani L.D. Toxicon 46:418-429(2005) [PubMed: 16026809] [Abstract] Cited for: PROTEIN SEQUENCE, MASS SPECTROMETRY. Tissue: Venom.

Cross-references

3D structure databases
ModBase	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

KAX2C_CENEL

Accession

Primary (citable) accession number: P0C165

Entry history

Integrated into UniProtKB/Swiss-Prot:	March 7, 2006
Last sequence update:	March 7, 2006
Last modified:	June 16, 2009
This is version 16 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

Tox-Prot (Toxin Annotation Project)