Reviewed, UniProtKB/Swiss-Prot Q9NII7 (KAX36_MESMA)

Names and origin

Protein names	Recommended name:     Potassium channel toxin alpha-KTx 3.6 Alternative name(s):     Kaliotoxin     BmKTX
Organism	Mesobuthus martensii (Manchurian scorpion) (Buthus martensii)
Taxonomic identifier	34649 [NCBI]
Taxonomic lineage	Eukaryota › Metazoa › Arthropoda › Chelicerata › Arachnida › Scorpiones › Buthida › Buthoidea › Buthidae › Mesobuthus

Protein attributes

Sequence length	60 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	Potent blocker of potassium channels.
Subcellular location	Secreted.
Tissue specificity	Expressed by the venom gland.
Toxic dose	LD50 is 2.0 µg/kg by intracerebroventricular injection into mice. Ref.3
Sequence similarities	Belongs to the short scorpion toxin superfamily. Potassium channel inhibitor family. Alpha-KTx 3 subfamily.

Ontologies

Keywords
Cellular component	Secreted
Domain	Signal
Molecular function	Ionic channel inhibitor 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: 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 – 22

22

Ref.3

Chain

23 – 59

37

Potassium channel toxin alpha-KTx 3.6

PRO_0000035314

Amino acid modifications

Modified residue

59

1

Lysine amide

Disulfide bond

29 ↔ 49

Ref.4

Disulfide bond

35 ↔ 54

Ref.4

Disulfide bond

39 ↔ 56

Ref.4

Experimental info

Sequence conflict

14

1

C → S in AAD47376. Ref.2

Secondary structure

1

.

.

.

.

.

.

.

.

60

Helix Strand Turn

Details...

Turn

32 – 35

4

Helix

36 – 41

6

Beta strand

47 – 49

3

Beta strand

51 – 56

6

Sequences

	Sequence		Length	Mass (Da)
	Q9NII7-1 [UniParc]. Last modified October 1, 2000. Version 1. Checksum: 6B0985E1223D9E67	FASTA	60	6,462
	10 20 30 40 50 60 MKVFFAVLIT LFICSMIIGI HGVGINVKCK HSGQCLKPCK DAGMRFGKCI NGKCDCTPKG

References

[1]	"Genomic organization of three novel toxins from the scorpion Buthus martensi Karsch that are active on potassium channels." Dai L., Wu J.-J., Gu Y.-H., Lan Z.-D., Ling M.-H., Chi C.-W. Biochem. J. 346:805-809(2000) [PubMed: 10698710] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA].
[2]	Wu J.-J., Dai L., Chi C.-W. Submitted (JUL-1998) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [MRNA].
[3]	"Purification, characterization, and synthesis of three novel toxins from the Chinese scorpion Buthus martensi, which act on K+ channels." Romi-Lebrun R., Lebrun B., Martin-Eauclaire M.-F., Ishiguro M., Escoubas P., Wu F.Q., Hisada M., Pongs O., Nakajima T. Biochemistry 36:13473-13482(1997) [PubMed: 9354615] [Abstract] Cited for: PROTEIN SEQUENCE OF 23-59, LETHAL DOSE, SYNTHESIS, CHARACTERIZATION.
[4]	"Solution structure of BmKTX, a K+ blocker toxin from the Chinese scorpion Buthus Martensi." Renisio J.G., Romi-Lebrun R., Blanc E., Bornet O., Nakajima T., Darbon H. Proteins 38:70-78(2000) [PubMed: 10651040] [Abstract] Cited for: STRUCTURE BY NMR OF 23-59, DISULFIDE BONDS.
+	Additional computationally mapped references.

Cross-references

Sequence databases

EMBLGenBankDDBJ

AF208298 Genomic DNA. Translation: AAF63970.1.
AF079062 mRNA. Translation: AAD47376.1.

3D structure databases

PDBPDBe

Entry	Method	Resolution (Å)	Chain	Positions	PDBsum
1BKT	NMR	-	A	23-59	[»]
2K4U	NMR	-	A	23-59	[»]

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

KAX36_MESMA

Accession

Primary (citable) accession number: Q9NII7
Secondary accession number(s): Q9UAC7

Entry history

Integrated into UniProtKB/Swiss-Prot:	December 19, 2001
Last sequence update:	October 1, 2000
Last modified:	June 16, 2009
This is version 58 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

Tox-Prot (Toxin Annotation Project)