P55928 (KAX72_PANIM) Reviewed, UniProtKB/Swiss-Prot

Names and origin

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

Protein attributes

Sequence length	35 AA.
Sequence status	Complete.
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.
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 7 subfamily.

Ontologies

Keywords
Cellular component	Secreted
Molecular function	Ion channel impairing toxin 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: 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 – 35

35

Potassium channel toxin alpha-KTx 7.2

PRO_0000044911

Sites

Site

24

1

Basic residue of the functional dyad By similarity

Site

33

1

Aromatic residue of the functional dyad By similarity

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 [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] [Europe PMC] [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] [Europe PMC] [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] [Europe PMC] [Abstract] Cited for: STRUCTURE BY NMR, DISULFIDE BONDS.

Cross-references

3D structure databases

PDBe
RCSB PDB
PDBj

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

ProteinModelPortal

P55928.

SMR

P55928. Positions 1-35.

ModBase

Search...

Protocols and materials databases

StructuralBiologyKnowledgebase

Search...

Family and domain databases

Gene3D

3.30.30.10. 1 hit.

InterPro

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

SUPFAM

SSF57095. SSF57095. 1 hit.

PROSITE

PS01138. SCORP_SHORT_TOXIN. 1 hit.
[Graphical view]

ProtoNet

Search...

Other

EvolutionaryTrace

P55928.

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:	May 1, 2013
This is version 71 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Animal Toxin Annotation Program