Reviewed, UniProtKB/Swiss-Prot P59290 (KAX39_BUTOC)

Names and origin

Protein names

Recommended name:
    Potassium channel toxin alpha-KTx 3.9
Alternative name(s):
    Kaliotoxin-3
      Short name=KTX-3

Gene names

Name:

KTX3

Organism

Buthus occitanus tunetanus (Common European scorpion)

Taxonomic identifier

6871 [NCBI]

Taxonomic lineage

Eukaryota › Metazoa › Arthropoda › Chelicerata › Arachnida › Scorpiones › Buthida › Buthoidea › Buthidae › Buthus

Protein attributes

Sequence length	37 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is not processed.
Protein existence	Evidence at protein level.

General annotation (Comments)

Function	Binds and inhibits potassium channels. Intracerebroventricular injection into mice induces paralyzing symptoms followed by death. Its binding affinity to rat brain synaptosomes is 5-fold lower than this of KTX 1.
Subcellular location	Secreted.
Tissue specificity	Expressed by the venom gland.
Toxic dose	LD50 is 5.5 µg/kg by intracerebroventricular injection. Ref.1
Sequence similarities	Belongs to the short scorpion toxin superfamily. Potassium channel inhibitor family. Alpha-KTx 3 subfamily.
Mass spectrometry	Molecular mass is 4376.27 Da from positions 1 - 37. Determined by ESI. Ref.1

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: 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
	Peptide	1 – 37	37	Potassium channel toxin alpha-KTx 3.9		PRO_0000044897
Regions
	Region	25 – 32	8	Interaction with Ca(2+)-activated K(+) channels Potential
Amino acid modifications
	Disulfide bond	7 ↔ 27		By similarity
	Disulfide bond	13 ↔ 32		By similarity
	Disulfide bond	17 ↔ 34		By similarity

Sequences

	Sequence		Length	Mass (Da)
	P59290-1 [UniParc]. Last modified February 12, 2003. Version 1. Checksum: D3A9805D5B55D8CB	FASTA	37	4,028
	10 20 30 VGIPVSCKHS GQCIKPCKDA GMRFGKCMNR KCDCTPK

References

[1]

"KTX3, the kaliotoxin from Buthus occitanus tunetanus scorpion venom: one of an extensive family of peptidyl ligands of potassium channels." Meki A., Mansuelle P., Laraba-Djebari F., Oughideni R., Rochat H., Martin-Eauclaire M.-F. Toxicon 38:105-111(2000) [PubMed: 10669015] [Abstract] Cited for: PROTEIN SEQUENCE, LETHAL DOSE, 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

KAX39_BUTOC

Accession

Primary (citable) accession number: P59290

Entry history

Integrated into UniProtKB/Swiss-Prot:	February 12, 2003
Last sequence update:	February 12, 2003
Last modified:	November 24, 2009
This is version 40 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

Tox-Prot (Toxin Annotation Project)