Reviewed, UniProtKB/Swiss-Prot P0C194 (KAX6B_OPIMA)

Names and origin

Protein names	Recommended name:     Potassium channel toxin alpha-KTx 6.11 Alternative name(s):     Male-specific potassium channel inhibitor IsTX
Organism	Opisthacanthus madagascariensis (Scorpion)
Taxonomic identifier	167108 [NCBI]
Taxonomic lineage	Eukaryota › Metazoa › Arthropoda › Chelicerata › Arachnida › Scorpiones › Iurida › Scorpionoidea › Liochelidae › Opisthacanthus

Protein attributes

Sequence length	63 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	Blocks voltage-gated potassium channels Kv1.1 (KCNA1) and Kv1.3 (KCNA3). Causes paralysis to crickets.
Subcellular location	Secreted.
Tissue specificity	Expressed by the venom gland. Only expressed by males.
Sequence similarities	Belongs to the short scorpion toxin superfamily. Potassium channel inhibitor family. Alpha-KTx 6 subfamily.
Mass spectrometry	Molecular mass is 4818.23 Da from positions 22 - 62. 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	3D-structure 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 – 21

21

Ref.1

Chain

22 – 62

41

Potassium channel toxin alpha-KTx 6.11

PRO_0000232654

Sites

Site

48

1

Critical for activity By similarity

Site

50

1

Important for activity By similarity

Site

51

1

Important for activity By similarity

Amino acid modifications

Disulfide bond

28 ↔ 49

Ref.1

Disulfide bond

34 ↔ 54

Ref.1

Disulfide bond

38 ↔ 56

Ref.1

Disulfide bond

44 ↔ 60

Ref.1

Secondary structure

1

.

.

.

.

.

.

.

63

Helix Strand Turn

Details...

Helix

31 – 40

10

Beta strand

48 – 50

3

Beta strand

53 – 55

3

Sequences

	Sequence		Length	Mass (Da)
	P0C194-1 [UniParc]. Last modified April 18, 2006. Version 1. Checksum: C9BDC4E26532BB26	FASTA	63	7,324
	10 20 30 40 50 60 MKVAYLLVLF TIMMLANDAS LVHTNIPCRG TSDCYEPCEK KYNCARAKCM NRHCNCYNNC PWR

References

[1]

"Solution structure of IsTX. A male scorpion toxin from Opisthacanthus madagascariensis (Ischnuridae)." Yamaji N., Dai L., Sugase K., Andriantsiferana M., Nakajima T., Iwashita T. Eur. J. Biochem. 271:3855-3864(2004) [PubMed: 15373831] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA], PROTEIN SEQUENCE OF 22-62, DISULFIDE BONDS, SYNTHESIS OF 22-62, MASS SPECTROMETRY, STRUCTURE BY NMR OF 22-62. Tissue: Venom and Venom gland.

Cross-references

3D structure databases

PDBPDBe

Entry	Method	Resolution (Å)	Chain	Positions	PDBsum
1WMT	NMR	-	A	22-62	[»]

ModBase

Search...

Family and domain databases

InterPro

IPR001947. Scorpion_toxinS.
[Graphical view]

Pfam

PF00451. Toxin_2. 1 hit.
[Graphical view]

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

KAX6B_OPIMA

Accession

Primary (citable) accession number: P0C194

Entry history

Integrated into UniProtKB/Swiss-Prot:	April 18, 2006
Last sequence update:	April 18, 2006
Last modified:	June 16, 2009
This is version 18 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

Tox-Prot (Toxin Annotation Project)