Reviewed, UniProtKB/Swiss-Prot P55928 (KAX72_PANIM)

Names and origin

Protein names	Recommended name:     Potassium channel toxin alpha-KTx 7.2 Alternative name(s):     Toxin PiTX-K-beta     Pandinotoxin-beta     Potassium channel-blocking toxin 3       Short name=Pi-3       Short name=Pi3
Organism	Pandinus imperator (Emperor scorpion)
Taxonomic identifier	55084 [NCBI]
Taxonomic lineage	Eukaryota › Metazoa › Arthropoda › Chelicerata › Arachnida › Scorpiones › Iurida › Scorpionoidea › Scorpionidae › Scorpioninae › Pandinus

Protein attributes

Sequence length	35 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is not processed.
Protein existence	Evidence at protein level.

General annotation (Comments)

Function	Potent inhibitor of the A-type voltage-gated potassium channels. Most potent inhibitor of Kv1.2/KCNA2 channels. Reversibly block the Shaker B potassium-channels (Kv1.1 sub-family), but with a lower affinity than PiTX-K alpha. Ref.2
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 7 subfamily.

Ontologies

Keywords
Cellular component	Secreted
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

Peptide

1 – 35

35

Potassium channel toxin alpha-KTx 7.2

PRO_0000044911

Amino acid modifications

Disulfide bond

4 ↔ 25

Ref.3

Disulfide bond

10 ↔ 30

Ref.3

Disulfide bond

14 ↔ 32

Ref.3

Secondary structure

1

.

.

.

.

.

.

.

.

35

Helix Strand Turn

Details...

Helix

7 – 10

4

Helix

11 – 17

7

Beta strand

23 – 26

4

Beta strand

29 – 32

4

Sequences

	Sequence		Length	Mass (Da)
	P55928-1 [UniParc]. Last modified November 1, 1997. Version 1. Checksum: DFCC26880D4C792A	FASTA	35	4,072
	10 20 30 TISCTNEKQC YPHCKKETGY PNAKCMNRKC KCFGR

References

[1]	"Three new toxins from the scorpion Pandinus imperator selectively block certain voltage-gated K+ channels." Rogowski R.S., Collins J.H., O'Neill T.J., Gustafson T.A., Werkman T.R., Rogawski M.A., Tenenholz T.C., Weber D.J., Blaustein M.P. Mol. Pharmacol. 50:1167-1177(1996) [PubMed: 8913348] [Abstract] Cited for: PROTEIN SEQUENCE. Tissue: Venom.
[2]	"Two novel toxins from the venom of the scorpion Pandinus imperator show that the N-terminal amino acid sequence is important for their affinities towards Shaker B K+ channels." Gomez-Lagunas F., Olamendi-Portugal T., Zamudio F.Z., Possani L.D. J. Membr. Biol. 152:49-56(1996) [PubMed: 8660410] [Abstract] Cited for: PROTEIN SEQUENCE, FUNCTION. Tissue: Venom.
[3]	"Structural and functional differences of two toxins from the scorpion Pandinus imperator." Klenk K.C., Tenenholz T.C., Matteson D.R., Rogowski R.S., Blaustein M.P., Weber D.J. Proteins 38:441-449(2000) [PubMed: 10707030] [Abstract] Cited for: STRUCTURE BY NMR, DISULFIDE BONDS.

Cross-references

3D structure databases

PDBPDBe

Entry	Method	Resolution (Å)	Chain	Positions	PDBsum
1C49	NMR	-	A	1-35	[»]

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

KAX72_PANIM

Accession

Primary (citable) accession number: P55928

Entry history

Integrated into UniProtKB/Swiss-Prot:	November 1, 1997
Last sequence update:	November 1, 1997
Last modified:	June 16, 2009
This is version 61 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

Tox-Prot (Toxin Annotation Project)