Reviewed, UniProtKB/Swiss-Prot P0C908 (KAX3A_BUTOS)

Names and origin

Protein names	Recommended name:     Potassium channel toxin alpha-KTx 3.10 Alternative name(s):     BoiTx1
Organism	Buthus occitanus israelis (Common yellow scorpion)
Taxonomic identifier	539894 [NCBI]
Taxonomic lineage	Eukaryota › Metazoa › Arthropoda › Chelicerata › Arachnida › Scorpiones › Buthida › Buthoidea › Buthidae › Buthus

Protein attributes

Sequence length	59 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	Inhibits insect potassium channel. Is at least a hundred-fold more potent against the Drosophila Shaker channel than towards its mammalian homologs, Kv1.1/KCNA1 and Kv1.3/KCNA3. Other mammalian potassium channels (Kv2.1/KCNB1, Kir1.1/KCNJ1, Kv3.4/KCNC4, Kv4.2/KCND2, Kv7.1/KCNQ1, KCNQ2, KCNQ3 and ERG/KCNH) are even less affected by this toxin.
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 3 subfamily.
Mass spectrometry	Molecular mass is 4015.6 Da from positions 23 - 59. Determined by MALDI. Ref.1

Ontologies

Keywords
Cellular component	Secreted
Domain	Signal
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: 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
	Signal peptide	1 – 22	22	Ref.1
	Peptide	23 – 59	37	Potassium channel toxin alpha-KTx 3.10 Ref.1		PRO_0000368016
Amino acid modifications
	Disulfide bond	30 ↔ 50		By similarity
	Disulfide bond	36 ↔ 55		By similarity
	Disulfide bond	40 ↔ 57		By similarity

Sequences

	Sequence		Length	Mass (Da)
	P0C908-1 [UniParc]. Last modified April 14, 2009. Version 1. Checksum: FEE2327C83D2C862	FASTA	59	6,402
	10 20 30 40 50 MKVFFAVLIA LFVCSMVIGI HGGVPINVKC RGSRDCLDPC KKAGMRFGKC INSKCHCTP

References

[1]

"Isolation of the first toxin from the scorpion Buthus occitanus israelis showing preference for Shaker potassium channels." Kozminsky-Atias A., Somech E., Zilberberg N. FEBS Lett. 581:2478-2484(2007) [PubMed: 17490656] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA], PROTEIN SEQUENCE OF 23-59, MASS SPECTROMETRY. Tissue: Venom and Venom gland.

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

KAX3A_BUTOS

Accession

Primary (citable) accession number: P0C908

Entry history

Integrated into UniProtKB/Swiss-Prot:	April 14, 2009
Last sequence update:	April 14, 2009
Last modified:	November 24, 2009
This is version 3 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

Tox-Prot (Toxin Annotation Project)