P83112 (KAX1A_PARTR) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names	Recommended name: Potassium channel toxin alpha-KTx 1.10 Alternative name(s): Parabutoxin-3 Short name=PBTx3
Organism	Parabuthus transvaalicus (South African fattail scorpion)
Taxonomic identifier	170972 [NCBI]
Taxonomic lineage	Eukaryota › Metazoa › Arthropoda › Chelicerata › Arachnida › Scorpiones › Buthida › Buthoidea › Buthidae › Parabuthus

Protein attributes

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

General annotation (Comments)

Function	Reversibly blocks different types of Kv1/KCNA voltage-gated potassium channels. Ref.1
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 1 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 – 37	37	Potassium channel toxin alpha-KTx 1.10		PRO_0000044917
Sites
	Site	26	1	Basic residue of the functional dyad By similarity
	Site	35	1	Aromatic residue of the functional dyad By similarity
Amino acid modifications
	Disulfide bond	6 ↔ 27		By similarity
	Disulfide bond	12 ↔ 32		By similarity
	Disulfide bond	16 ↔ 34		By similarity
Experimental info
	Mutagenesis	24	1	N → F: 100-fold increase of affinity towards Kv1.1 channels, 5-fold increase in affinity towards Kv1.3 channels and no change in affinity towards Kv1.2 channels.

Sequences

	Sequence		Length	Mass (Da)
	P83112 [UniParc]. Last modified October 1, 2001. Version 1. Checksum: A4C9DF3AD856BE06	FASTA	37	4,280
	10 20 30 EVDMRCKSSK ECLVKCKQAT GRPNGKCMNR KCKCYPR

References

[1]	"Purification, characterization and biosynthesis of parabutoxin 3, a component of Parabuthus transvaalicus venom." Huys I., Dyason K., Waelkens E., Verdonck F., van Zyl J., du Plessis J., Mueller G.J., van der Walt J., Clynen E., Schoofs L., Tytgat J. Eur. J. Biochem. 269:1854-1865(2002) [PubMed: 11952787] [Abstract] Cited for: PROTEIN SEQUENCE, FUNCTION. Tissue: Venom.
[2]	"Evidence for a function-specific mutation in the neurotoxin, parabutoxin 3." Huys I., Tytgat J. Eur. J. Neurosci. 17:1786-1792(2003) [PubMed: 12752777] [Abstract] Cited for: MUTAGENESIS.
+	Additional computationally mapped references.

Cross-references

3D structure databases
ProteinModelPortal	P83112.
SMR	P83112. Positions 2-36.
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

KAX1A_PARTR

Accession

Primary (citable) accession number: P83112

Entry history

Integrated into UniProtKB/Swiss-Prot:	December 19, 2001
Last sequence update:	October 1, 2001
Last modified:	November 16, 2011
This is version 47 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Animal Toxin Annotation Program