P82850 (KKX11_HETFU) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names	Recommended name: Potassium channel toxin kappa-KTx 1.1 Alternative name(s): Kappa-hefutoxin-1 Short name=Kappa-HfTx1
Organism	Heterometrus fulvipes (Indian black scorpion)
Taxonomic identifier	141248 [NCBI]
Taxonomic lineage	cellular organisms › Eukaryota › Opisthokonta › Metazoa › Eumetazoa › Bilateria › Protostomia › Ecdysozoa › Panarthropoda › Arthropoda › Chelicerata › Arachnida › Scorpiones › Iurida › Scorpionoidea › Scorpionidae › Scorpioninae › Heterometrus

Protein attributes

Sequence length	22 AA.
Sequence status	Complete.
Protein existence	Evidence at protein level

General annotation (Comments)

Function	Slows the activation kinetics of Kv1.3/KCNA3 currents, and blocks Kv1.3/KCNA3 and Kv1.2/KCNA2 potassium channels. This block is dose-dependent, voltage-independent, and reversible. Ref.1
Subcellular location	Secreted.
Tissue specificity	Expressed by the venom gland.
Domain	Has the structural arrangement of two alpha-helices stabilized by two disulfide bonds (CSalpha/alpha).
Miscellaneous	This toxin does not have effect on Kv1.1/KCNA1 currents (Ref.1).
Sequence similarities	Belongs to the short scorpion toxin superfamily. Potassium channel inhibitor kappa-KTx family. Kappa-KTx 1 subfamily.
Mass spectrometry	Molecular mass is 2655.4±0.2 Da from positions 1 - 22. Determined by ESI. Ref.1

Ontologies

Keywords
Cellular component	Secreted
Molecular function	Ion channel impairing toxin Neurotoxin Potassium channel inhibitor Toxin
PTM	Amidation Disulfide bond
Technical term	3D-structure 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 – 22

22

Potassium channel toxin kappa-KTx 1.1

PRO_0000044544

Amino acid modifications

Modified residue

22

1

Cysteine amide

Disulfide bond

4 ↔ 22

Ref.1

Disulfide bond

8 ↔ 18

Ref.1

Experimental info

Mutagenesis

5

1

Y → A: Loss of channels blocking. Same effect observed; when associated with A-19. Ref.1

Mutagenesis

19

1

K → A: Loss of channels blocking. Same effect observed; when associated with A-5. Ref.1

Secondary structure

1

.

.

.

.

.

.

22

Helix Strand Turn

Details...

Turn

4 – 6

3

Helix

7 – 12

6

Helix

17 – 21

5

Sequences

	Sequence		Length	Mass (Da)
	P82850 [UniParc]. Last modified March 1, 2001. Version 1. Checksum: 8FB555EB877C6E98	FASTA	22	2,660
	10 20 GHACYRNCWR EGNDEETCKE RC

References

[1]

"Kappa-hefutoxin1, a novel toxin from the scorpion Heterometrus fulvipes with unique structure and function. Importance of the functional diad in potassium channel selectivity." Srinivasan K.N., Sivaraja V., Huys I., Sasaki T., Cheng B., Kumar T.K.S., Sato K., Tytgat J., Yu C., San B.C.C., Ranganathan S., Bowie H.J., Kini R.M., Gopalakrishnakone P. J. Biol. Chem. 277:30040-30047(2002) [PubMed] [Europe PMC] [Abstract] Cited for: PROTEIN SEQUENCE, FUNCTION, AMIDATION, STRUCTURE BY NMR, DISULFIDE BONDS, MASS SPECTROMETRY, MUTAGENESIS OF TYR-5; LYS-19 AND 5-TYR--LYS-19. Tissue: Venom.

Cross-references

3D structure databases

PDBe
RCSB PDB
PDBj

Entry	Method	Resolution (Å)	Chain	Positions	PDBsum
1HP9	NMR	-	A	1-22	[»]

ModBase

Search...

Protein family/group databases

TCDB

8.B.2.1.1. short scorpion toxin (SST) superfamily.

Protocols and materials databases

StructuralBiologyKnowledgebase

Search...

Family and domain databases

InterPro

IPR012630. Toxin_25.
[Graphical view]

Pfam

PF08095. Toxin_25. 1 hit.
[Graphical view]

ProtoNet

Search...

Other

EvolutionaryTrace

P82850.

Entry information

Entry name

KKX11_HETFU

Accession

Primary (citable) accession number: P82850

Entry history

Integrated into UniProtKB/Swiss-Prot:	May 4, 2001
Last sequence update:	March 1, 2001
Last modified:	April 3, 2013
This is version 57 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Animal Toxin Annotation Program