P55927 (KAX71_PANIM) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
Potassium channel toxin alpha-KTx 7.1

Alternative name(s):
Pandinotoxin-alpha
Potassium channel-blocking toxin 2
Short name=Pi-2
Short name=Pi2
Toxin PiTX-K-alpha

Gene names

Name:

PTX-1

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	47 AA.
Sequence status	Fragment.
Sequence processing	The displayed sequence is further processed into a mature form.
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). Ref.3
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
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: 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

Signal peptide

‹1 – 12

›12

Ref.2 Ref.3

Peptide

13 – 47

35

Potassium channel toxin alpha-KTx 7.1 Ref.2 Ref.3

PRO_0000035328

Sites

Site

36

1

Basic residue of the functional dyad By similarity

Site

45

1

Aromatic residue of the functional dyad By similarity

Amino acid modifications

Disulfide bond

16 ↔ 37

Ref.4

Disulfide bond

22 ↔ 42

Ref.4

Disulfide bond

26 ↔ 44

Ref.4

Experimental info

Non-terminal residue

1

1

Secondary structure

1

.

.

.

.

.

.

.

47

Helix Strand Turn

Details...

Helix

19 – 29

11

Beta strand

35 – 38

4

Beta strand

41 – 45

5

Sequences

	Sequence		Length	Mass (Da)
	P55927 [UniParc]. Last modified December 15, 1998. Version 2. Checksum: 21B8BF110A37BD7C	FASTA	47	5,434
	10 20 30 40 RGSVDYKDDD DKTISCTNPK QCYPHCKKET GYPNAKCMNR KCKCFGR

References

[1]	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. Submitted (NOV-1996) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [MRNA].
[2]	"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 OF 13-47. Tissue: Venom.
[3]	"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 OF 13-47, FUNCTION. Tissue: Venom.
[4]	"Solution structure for Pandinus toxin K-alpha (PiTX-K alpha), a selective blocker of A-type potassium channels." Tenenholz T.C., Rogowski R.S., Collins J.H., Blaustein M.P., Weber D.J. Biochemistry 36:2763-2771(1997) [PubMed: 9062103] [Abstract] Cited for: STRUCTURE BY NMR OF 13-47, DISULFIDE BONDS.
+	Additional computationally mapped references.

Cross-references

Sequence databases

EMBL
GenBank
DDBJ

U79579 mRNA. Translation: AAB52576.1.

PIR

T10471.

3D structure databases

PDBe
RCSB PDB
PDBj

Entry	Method	Resolution (Å)	Chain	Positions	PDBsum
2PTA	NMR	-	A	13-47	[»]

ProteinModelPortal

P55927.

SMR

P55927. Positions 13-47.

ModBase

Search...

Protocols and materials databases

StructuralBiologyKnowledgebase

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

KAX71_PANIM

Accession

Primary (citable) accession number: P55927

Entry history

Integrated into UniProtKB/Swiss-Prot:	November 1, 1997
Last sequence update:	December 15, 1998
Last modified:	November 16, 2011
This is version 71 of the entry and version 2 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Animal Toxin Annotation Program