P59869 (KAX54_MESTA) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names	Recommended name: Potassium channel toxin alpha-KTx 5.4 Alternative name(s): Tamapin
Organism	Mesobuthus tamulus (Eastern Indian scorpion) (Buthus tamulus)
Taxonomic identifier	34647 [NCBI]
Taxonomic lineage	cellular organisms › Eukaryota › Opisthokonta › Metazoa › Eumetazoa › Bilateria › Protostomia › Ecdysozoa › Panarthropoda › Arthropoda › Chelicerata › Arachnida › Scorpiones › Buthida › Buthoidea › Buthidae › Mesobuthus

Protein attributes

Sequence length	31 AA.
Sequence status	Complete.
Protein existence	Evidence at protein level

General annotation (Comments)

Function	Blocks small conductance calcium-activated potassium channels in pyramidal neurons of the hippocampus. Displays a unique, remarkable selectivity for SK2/KCNN2 versus SK1/KCNN1 and SK3/KCNN3 channels. Ref.1
Subcellular location	Secreted.
Tissue specificity	Expressed by the venom gland.
Domain	Has the structural arrangement of an alpha-helix connected to a beta-sheet by disulfide bonds (CSalpha/beta).
Sequence similarities	Belongs to the short scorpion toxin superfamily. Potassium channel inhibitor family. Alpha-KTx 5 subfamily.
Mass spectrometry	Molecular mass is 3457.9±0.2 Da from positions 1 - 31. 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 – 31

31

Potassium channel toxin alpha-KTx 5.4

PRO_0000044930

Amino acid modifications

Modified residue

31

1

Tyrosine amide Probable

Disulfide bond

3 ↔ 21

Ref.2

Disulfide bond

8 ↔ 26

Ref.2

Disulfide bond

12 ↔ 28

Ref.2

Secondary structure

1

.

.

.

.

.

.

.

.

31

Helix Strand Turn

Details...

Helix

5 – 12

8

Helix

13 – 15

3

Beta strand

17 – 20

4

Beta strand

27 – 29

3

Sequences

	Sequence		Length	Mass (Da)
	P59869 [UniParc]. Last modified September 26, 2003. Version 1. Checksum: FE643CDC54CA415C	FASTA	31	3,465
	10 20 30 AFCNLRRCEL SCRSLGLLGK CIGEECKCVP Y

References

[1]

"Tamapin, a venom peptide from the Indian red scorpion (Mesobuthus tamulus) that targets small conductance Ca2+-activated K+ channels and afterhyperpolarization currents in central neurons." Pedarzani P., D'hoedt D., Doorty K.B., Wadsworth J.D.F., Joseph J.S., Jeyaseelan K., Kini R.M., Gadre S.V., Sapatnekar S.M., Stocker M., Strong P.N. J. Biol. Chem. 277:46101-46109(2002) [PubMed] [Europe PMC] [Abstract] Cited for: PROTEIN SEQUENCE, MASS SPECTROMETRY, FUNCTION. Tissue: Venom.

[2]

"Solution structure of gs-alpha-ktx5.4 synthetic scorpion toxin." Del Rio-Portilla F., Ramirez-Cordero B.E., Saucedo-Yanez L.B., Cano-Sanchez P., Flores-Solis R.H.-L., Pedarzani P., Dhoedet D., Doorty K.B., Wadsworth D.J.F., Jeyaseelan J.K., Kini R.M., Gadre S.V., Sapatnekar S.M., Strong M.S. Submitted (MAY-2010) to the PDB data bank Cited for: STRUCTURE BY NMR, DISULFIDE BONDS.

Cross-references

3D structure databases

PDBe
RCSB PDB
PDBj

Entry	Method	Resolution (Å)	Chain	Positions	PDBsum
2CF1	model	-	A	1-31	[»]
2KY3	NMR	-	A	1-31	[»]

ProteinModelPortal

P59869.

SMR

P59869. Positions 2-30.

ModBase

Search...

Protocols and materials databases

StructuralBiologyKnowledgebase

Search...

Family and domain databases

InterPro

IPR003614. Scorpion_toxin-like.
IPR001947. Scorpion_toxinS_K_inh.
[Graphical view]

Pfam

PF00451. Toxin_2. 1 hit.
[Graphical view]

SUPFAM

SSF57095. SSF57095. 1 hit.

PROSITE

PS01138. SCORP_SHORT_TOXIN. 1 hit.
[Graphical view]

ProtoNet

Search...

Entry information

Entry name

KAX54_MESTA

Accession

Primary (citable) accession number: P59869

Entry history

Integrated into UniProtKB/Swiss-Prot:	September 26, 2003
Last sequence update:	September 26, 2003
Last modified:	May 1, 2013
This is version 45 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Animal Toxin Annotation Program