Reviewed, UniProtKB/Swiss-Prot Q9U8D1 (KAX92_MESMA)

Names and origin

Protein names	Recommended name:     Potassium channel toxin alpha-KTx 9.2 Alternative name(s):     Neurotoxin BmP03     Potassium ion channel blocker P03
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	56 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 small conductance calcium-activated potassium channels (KCNN, SK). Low toxicity by intracerebroventricular injection into mice.
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 9 subfamily.
Mass spectrometry	Molecular mass is 2935.29 Da from positions 29 - 56. Determined by MALDI. Ref.3

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 – 28

28

Ref.3

Peptide

29 – 56

28

Potassium channel toxin alpha-KTx 9.2 Ref.3

PRO_0000035350

Amino acid modifications

Disulfide bond

31 ↔ 47

Ref.4

Disulfide bond

34 ↔ 52

Ref.4

Disulfide bond

38 ↔ 54

Ref.4

Secondary structure

1

.

.

.

.

.

.

.

56

Helix Strand Turn

Details...

Helix

36 – 38

3

Beta strand

40 – 42

3

Beta strand

49 – 51

3

Sequences

	Sequence		Length	Mass (Da)
	Q9U8D1-1 [UniParc]. Last modified May 1, 2000. Version 1. Checksum: 70953032007E8672	FASTA	56	6,001
	10 20 30 40 50 MSRLFTLVLI VLAMNVMMAI ISDPVVEAVG CEECPMHCKG KNANPTCDDG VCNCNV

References

[1]	"Genomic organization of three neurotoxins active on small conductance Ca2+-activated potassium channels from the scorpion Buthus martensi Karsch." Wu J.-J., Dai L., Lan Z.-D., Chi C.-W. FEBS Lett. 452:360-364(1999) [PubMed: 10386622] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA]. Tissue: Venom gland.
[2]	"Molecular cloning and sequencing of two 'short chain' and two 'long chain' K(+) channel-blocking peptides from the Chinese scorpion Buthus martensii Karsch." Zhu S.-Y., Li W.-X., Zeng X.-C., Jiang D.-H., Mao X., Liu H. FEBS Lett. 457:509-514(1999) [PubMed: 10471839] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA]. Tissue: Venom gland.
[3]	"Characterization of four toxins from Buthus martensi scorpion venom, which act on apamin-sensitive Ca2+-activated K+ channels." Romi-Lebrun R., Martin-Eauclaire M.-F., Escoubas P., Wu F.Q., Lebrun B., Hisada M., Nakajima T. Eur. J. Biochem. 245:457-464(1997) [PubMed: 9151979] [Abstract] Cited for: PROTEIN SEQUENCE OF 29-56, MASS SPECTROMETRY.
[4]	"Three-dimensional structure of BmP03 from venom of scorpion Buthus martensii Karsch." He F., Li Y., Wu G., Cao C., Wu H. Acta Chim. Sin. 58:850-855(2000) Cited for: STRUCTURE BY NMR OF 29-56, DISULFIDE BONDS.

Cross-references

Sequence databases

EMBLGenBankDDBJ

AF097408 Genomic DNA. Translation: AAF01253.1.
AF156170 mRNA. Translation: AAF29463.1.

3D structure databases

PDBPDBe

Entry	Method	Resolution (Å)	Chain	Positions	PDBsum
1WM8	NMR	-	A	29-56	[»]

ModBase

Search...

Family and domain databases

InterPro

IPR008911. Toxin_6.
[Graphical view]

Pfam

PF05453. Toxin_6. 1 hit.
[Graphical view]

PROSITE

PS01138. SCORP_SHORT_TOXIN. False negative.
[Graphical view]

ProtoNet

Search...

Entry information

Entry name

KAX92_MESMA

Accession

Primary (citable) accession number: Q9U8D1

Entry history

Integrated into UniProtKB/Swiss-Prot:	December 19, 2001
Last sequence update:	May 1, 2000
Last modified:	November 24, 2009
This is version 50 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

Tox-Prot (Toxin Annotation Project)