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Protein

Potassium channel toxin alpha-KTx 2.2

Gene
N/A
Organism
Centruroides margaritatus (Scorpion)
Status
Reviewed-Annotation score: Annotation score: 3 out of 5-Experimental evidence at protein leveli

Functioni

Potent inhibitor of voltage-gated potassium channels such as Kv1.1/KCNA1 (IC50=0.144 nM), Kv1.2/KCNA2 (IC50=0.675 nM), Kv1.3/KCNA3 (IC50=0.23 nM) and Shaker (Kd=160 nM).1 Publication

Sites

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Sitei28 – 281Basic residue of the functional dyadBy similarity
Sitei37 – 371Aromatic residue of the functional dyadBy similarity

GO - Molecular functioni

GO - Biological processi

Complete GO annotation...

Keywords - Molecular functioni

Ion channel impairing toxin, Neurotoxin, Potassium channel impairing toxin, Toxin, Voltage-gated potassium channel impairing toxin

Protein family/group databases

TCDBi8.B.8.1.3. the -ktx15 scorpion toxin (-ktx15) family.

Names & Taxonomyi

Protein namesi
Recommended name:
Potassium channel toxin alpha-KTx 2.2
Alternative name(s):
Margatoxin1 Publication
Short name:
MgTX1 Publication
OrganismiCentruroides margaritatus (Scorpion)
Taxonomic identifieri29018 [NCBI]
Taxonomic lineageiEukaryotaMetazoaEcdysozoaArthropodaChelicerataArachnidaScorpionesButhidaButhoideaButhidaeCentruroides

Subcellular locationi

  • Secreted 1 Publication

GO - Cellular componenti

Complete GO annotation...

Keywords - Cellular componenti

Secreted

PTM / Processingi

Molecule processing

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Peptidei1 – 3939Potassium channel toxin alpha-KTx 2.21 PublicationPRO_0000044904Add
BLAST

Amino acid modifications

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Disulfide bondi7 ↔ 291 Publication
Disulfide bondi13 ↔ 341 Publication
Disulfide bondi17 ↔ 361 Publication

Keywords - PTMi

Disulfide bond

Expressioni

Tissue specificityi

Expressed by the venom gland.1 Publication

Structurei

Secondary structure

1
39
Legend: HelixTurnBeta strand
Show more details
Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Helixi10 – 134Combined sources
Helixi14 – 207Combined sources
Beta strandi26 – 305Combined sources
Beta strandi33 – 375Combined sources

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
EntryMethodResolution (Å)ChainPositionsPDBsum
1MTXNMR-A1-39[»]
ProteinModelPortaliP40755.
SMRiP40755. Positions 1-39.
ModBaseiSearch...
MobiDBiSearch...

Miscellaneous databases

EvolutionaryTraceiP40755.

Family & Domainsi

Region

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Regioni37 – 393Interaction with Kv1.3 channelsSequence analysis

Domaini

Has the structural arrangement of an alpha-helix connected to a beta-sheet by disulfide bonds (CSalpha/beta).

Sequence similaritiesi

Family and domain databases

Gene3Di3.30.30.10. 1 hit.
InterProiIPR003614. Scorpion_toxin-like.
IPR001947. Scorpion_toxinS_K_inh.
[Graphical view]
PfamiPF00451. Toxin_2. 1 hit.
[Graphical view]
PRINTSiPR00286. CHARYBDTOXIN.
ProDomiPD003586. Scorpion_toxinS. 1 hit.
[Graphical view] [Entries sharing at least one domain]
SUPFAMiSSF57095. SSF57095. 1 hit.
PROSITEiPS01138. SCORP_SHORT_TOXIN. 1 hit.
[Graphical view]

Sequencei

Sequence statusi: Complete.

P40755-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30 
TIINVKCTSP KQCLPPCKAQ FGQSAGAKCM NGKCKCYPH
Length:39
Mass (Da):4,185
Last modified:February 1, 1995 - v1
Checksum:i0FB748318014BE0D
GO

Sequence databases

PIRiA48523.

Cross-referencesi

Sequence databases

PIRiA48523.

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
EntryMethodResolution (Å)ChainPositionsPDBsum
1MTXNMR-A1-39[»]
ProteinModelPortaliP40755.
SMRiP40755. Positions 1-39.
ModBaseiSearch...
MobiDBiSearch...

Protein family/group databases

TCDBi8.B.8.1.3. the -ktx15 scorpion toxin (-ktx15) family.

Protocols and materials databases

Structural Biology KnowledgebaseSearch...

Miscellaneous databases

EvolutionaryTraceiP40755.

Family and domain databases

Gene3Di3.30.30.10. 1 hit.
InterProiIPR003614. Scorpion_toxin-like.
IPR001947. Scorpion_toxinS_K_inh.
[Graphical view]
PfamiPF00451. Toxin_2. 1 hit.
[Graphical view]
PRINTSiPR00286. CHARYBDTOXIN.
ProDomiPD003586. Scorpion_toxinS. 1 hit.
[Graphical view] [Entries sharing at least one domain]
SUPFAMiSSF57095. SSF57095. 1 hit.
PROSITEiPS01138. SCORP_SHORT_TOXIN. 1 hit.
[Graphical view]
ProtoNetiSearch...

Publicationsi

  1. "Purification, characterization, and biosynthesis of margatoxin, a component of Centruroides margaritatus venom that selectively inhibits voltage-dependent potassium channels."
    Garcia-Calvo M., Leonard R.J., Novick J., Stevens S.P., Schmalhofer W., Kaczorowski G.J., Garcia M.L.
    J. Biol. Chem. 268:18866-18874(1993) [PubMed] [Europe PMC] [Abstract]
    Cited for: PROTEIN SEQUENCE, FUNCTION, SUBCELLULAR LOCATION.
    Tissue: Venom.
  2. "Chemical synthesis and structure-function studies of margatoxin, a potent inhibitor of voltage-dependent potassium channel in human T lymphocytes."
    Bednarek M.A., Bugianesi R.M., Leonard R.J., Felix J.P.
    Biochem. Biophys. Res. Commun. 198:619-625(1994) [PubMed] [Europe PMC] [Abstract]
    Cited for: SYNTHESIS, DISULFIDE BONDS.
  3. "Subunit composition of brain voltage-gated potassium channels determined by hongotoxin-1, a novel peptide derived from Centruroides limbatus venom."
    Koschak A., Bugianesi R.M., Mitterdorfer J., Kaczorowski G.J., Garcia M.L., Knaus H.-G.
    J. Biol. Chem. 273:2639-2644(1998) [PubMed] [Europe PMC] [Abstract]
    Cited for: FUNCTION, ACTIVITY PROFILE.
  4. "Determination of the three-dimensional structure of margatoxin by 1H, 13C, 15N triple-resonance nuclear magnetic resonance spectroscopy."
    Johnson B.A., Stevens S.P., Williamson J.M.
    Biochemistry 33:15061-15070(1994) [PubMed] [Europe PMC] [Abstract]
    Cited for: STRUCTURE BY NMR, DISULFIDE BONDS.

Entry informationi

Entry nameiKAX22_CENMA
AccessioniPrimary (citable) accession number: P40755
Entry historyi
Integrated into UniProtKB/Swiss-Prot: February 1, 1995
Last sequence update: February 1, 1995
Last modified: January 20, 2016
This is version 84 of the entry and version 1 of the sequence. [Complete history]
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programAnimal Toxin Annotation Program

Miscellaneousi

Keywords - Technical termi

3D-structure, Direct protein sequencing

Documents

  1. PDB cross-references
    Index of Protein Data Bank (PDB) cross-references
  2. Scorpion potassium channel toxins
    Nomenclature of scorpion potassium channel toxins and list of entries
  3. SIMILARITY comments
    Index of protein domains and families

Similar proteinsi

Links to similar proteins from the UniProt Reference Clusters (UniRef) at 100%, 90% and 50% sequence identity:
100%UniRef100 combines identical sequences and sub-fragments with 11 or more residues from any organism into one UniRef entry.
90%UniRef90 is built by clustering UniRef100 sequences that have at least 90% sequence identity to, and 80% overlap with, the longest sequence (a.k.a seed sequence).
50%UniRef50 is built by clustering UniRef90 seed sequences that have at least 50% sequence identity to, and 80% overlap with, the longest sequence in the cluster.