P60210 (KAX44_TITOB) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names	Recommended name: Potassium channel toxin alpha-KTx 4.4 Alternative name(s): Toxin Tc30 Toxin To30
Organism	Tityus obscurus (Amazonian scorpion) (Tityus cambridgei)
Taxonomic identifier	184226 [NCBI]
Taxonomic lineage	cellular organisms › Eukaryota › Opisthokonta › Metazoa › Eumetazoa › Bilateria › Protostomia › Ecdysozoa › Panarthropoda › Arthropoda › Chelicerata › Arachnida › Scorpiones › Buthida › Buthoidea › Buthidae › Tityus

Protein attributes

Sequence length	37 AA.
Sequence status	Complete.
Protein existence	Evidence at protein level

General annotation (Comments)

Function	Reversible blocker of both Shaker B potassium channels (high affinity), and Kv1.3/KCNA3 potassium channels of human T lymphocytes (low affinity). Ref.1
Subcellular location	Secreted Ref.2.
Tissue specificity	Expressed by the venom gland. Ref.2
Sequence similarities	Belongs to the short scorpion toxin superfamily. Potassium channel inhibitor family. Alpha-KTx 4 subfamily.
Mass spectrometry	Molecular mass is 3871.8 Da from positions 1 - 37. Determined by ESI. Ref.1 Ref.2

Ontologies

Keywords
Cellular component	Secreted
Molecular function	Ion channel impairing toxin Neurotoxin Potassium channel inhibitor Toxin
PTM	Disulfide bond
Technical term	Direct protein sequencing
Gene Ontology (GO)
Biological_process	pathogenesis Inferred from direct assay Ref.1. Source: UniProtKB
Cellular_component	extracellular region Inferred from direct assay Ref.2. Source: UniProtKB
Molecular_function	potassium channel inhibitor activity Inferred from direct assay Ref.1. Source: UniProtKB
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 4.4		PRO_0000044920
Regions
	Region	26 – 33	8	Interaction with Ca(2+)-activated K(+) channels Potential
Sites
	Site	27	1	Basic residue of the functional dyad By similarity
	Site	36	1	Aromatic residue of the functional dyad By similarity
Amino acid modifications
	Disulfide bond	7 ↔ 28		By similarity
	Disulfide bond	13 ↔ 33		By similarity
	Disulfide bond	17 ↔ 35		By similarity

Sequences

	Sequence		Length	Mass (Da)
	P60210 [UniParc]. Last modified January 16, 2004. Version 1. Checksum: 6B17BB651C3E3449	FASTA	37	3,878
	10 20 30 VFINVKCRGS KECLPACKAA VGKAAGKCMN GKCKCYP

References

[1]

"Two novel toxins from the Amazonian scorpion Tityus cambridgei that block Kv1.3 and Shaker B K(+)-channels with distinctly different affinities." Batista C.V.F., Gomez-Lagunas F., Rodriguez de la Vega R.C., Hajdu P., Panyi G., Gaspar R., Possani L.D. Biochim. Biophys. Acta 1601:123-131(2002) [PubMed] [Europe PMC] [Abstract] Cited for: PROTEIN SEQUENCE, FUNCTION, MASS SPECTROMETRY. Tissue: Venom.

[2]

"Proteomics of the venom from the Amazonian scorpion Tityus cambridgei and the role of prolines on mass spectrometry analysis of toxins." Batista C.V.F., del Pozo L., Zamudio F.Z., Contreras S., Becerril B., Wanke E., Possani L.D. J. Chromatogr. B 803:55-66(2004) [PubMed] [Europe PMC] [Abstract] Cited for: PROTEIN SEQUENCE OF 1-10, SUBCELLULAR LOCATION, TISSUE SPECIFICITY, MASS SPECTROMETRY. Tissue: Venom.

Cross-references

3D structure databases
ProteinModelPortal	P60210.
SMR	P60210. Positions 1-37.
ModBase	Search...
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Family and domain databases
Gene3D	3.30.30.10. 1 hit.
InterPro	IPR003614. Scorpion_toxin-like. IPR001947. Scorpion_toxinS_K_inh. [Graphical view]
Pfam	PF00451. Toxin_2. 1 hit. [Graphical view]
PRINTS	PR00286. CHARYBDTOXIN.
SUPFAM	SSF57095. SSF57095. 1 hit.
PROSITE	PS01138. SCORP_SHORT_TOXIN. 1 hit. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

KAX44_TITOB

Accession

Primary (citable) accession number: P60210

Entry history

Integrated into UniProtKB/Swiss-Prot:	January 16, 2004
Last sequence update:	January 16, 2004
Last modified:	May 1, 2013
This is version 37 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Animal Toxin Annotation Program