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Entry version 75 (22 Nov 2017)
Sequence version 1 (01 Jun 2001)
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Protein

Potassium channel toxin gamma-KTx 2.1

Gene
N/A
Organism
Mesobuthus eupeus (Lesser Asian scorpion) (Buthus eupeus)
Status
Reviewed-Annotation score:

Annotation score:5 out of 5

<p>The annotation score provides a heuristic measure of the annotation content of a UniProtKB entry or proteome. This score <strong>cannot</strong> be used as a measure of the accuracy of the annotation as we cannot define the ‘correct annotation’ for any given protein.<p><a href='/help/annotation_score' target='_top'>More...</a></p>
-Experimental evidence at protein leveli <p>This indicates the type of evidence that supports the existence of the protein. Note that the ‘protein existence’ evidence does not give information on the accuracy or correctness of the sequence(s) displayed.<p><a href='/help/protein_existence' target='_top'>More...</a></p>

<p>This section provides any useful information about the protein, mostly biological knowledge.<p><a href='/help/function_section' target='_top'>More...</a></p>Functioni

Blocks human and/or rat Kv11.1/KCNH2/ERG1, Kv11.2/KCNH6/ERG2 and Kv11.3/KCNH7/ERG3 by binding to channel outer vestibule (S5P domain) with a 1:1 stoichiometry. Inhibition data are the following: hERG1 (reversible, Kd=7.7 nM (PubMed:16497878), IC50=3.3 nM (PubMed:11136720), IC50=11.9 nM (PubMed:21205913)), rERG1 (reversible, Kd=19 nM) (PubMed:16497878), hERG2 (reversible, Kd=77 nM) (PubMed:16497878), rERG2 (irreversible, Kd=4.2 nM) (PubMed:16497878), hERG3 (reversible, Kd=11.5 nM) (PubMed:16497878) and rERG3 (reversible, Kd=747 nM) (PubMed:16497878) potassium channels. Has also a minimal effect on rat ELK1/KCNH4 potassium channels (9% inhibition at 100 nM (PubMed:15137031)). Both this toxin and CnErgTx1 (AC Q86QT3) share mechanism of action and have overlapping binding sites on ERG1 (PubMed:12719233). The potency of these two toxins is not affected by elevating potassium ion concentration from 2 to 98 mM (PubMed:12719233). In addition, at high toxin concentrations, block of ERG1 macroscopic currents by these two toxins is incomplete (88%) (PubMed:12719233). The blockade by this toxin is preferentially closed channel state-dependent, with a component of open, but not inactive state-dependent blockade (PubMed:12860380). This toxin produces a concentration-dependent prolongation of QTc in the isolated rabbit heart (16.3% at 100 nM) (PubMed:21205913).6 Publications

Miscellaneous

The inhibition potency of the toxin for ERG1 decreases as temperature increases (IC50=7.6 nM and IC50=15.3 nM at room temperature and 37 degrees Celsius, respectively), likely due to changes in the structure of the channel binding site.1 Publication
The toxin (at 100 nM) does not inhibit hEAG1/KCNH1, hBK/KCa1.1/KCNMA1, hSK1/KCa2.1/KCNN1, rSK2/KCa2.2/KCNN2, hIK/KCa3.1/KCNN4, KCNQ1+KCNE1, KCNQ2+KCNQ3 and KCNQ4 channels (PubMed:11136720). The toxin (at 50 nM) does not inhibit Kv1.2/KCNA2, Kv1.4/KCNA4, Kv2.1/KCNB1, Kv4.3/KCND3, Kir1.1/KCNJ1 (PubMed:15137031).2 Publications

Caution

Has been classified as a gamma-KTx toxin due to its molecular target (Kv11/ERG), but may be classified as an alpha-KTx since it shares a high level of homology in both primary and 3D structures with other alpha-KTx scorpion toxins. However, it is noteworthy that surface by which BeKm-1 interacts with ERG1 is formed by residues located in the alpha-helix and the following loop, while the traditional functional site of other alpha-KTxs is formed by residues on the beta-sheet.1 Publication

Sites

Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection describes interesting single amino acid sites on the sequence that are not defined in any other subsection. This subsection can be displayed in different sections (‘Function’, ‘PTM / Processing’, ‘Pathology and Biotech’) according to its content.<p><a href='/help/site' target='_top'>More...</a></p>Sitei39Crucial for Kv11/ERG channel binding, plugs its side chain into the channel selectivity filter2 Publications1
Sitei41Crucial for Kv11/ERG channel binding2 Publications1

<p>The <a href="http://www.geneontology.org/">Gene Ontology (GO)</a> project provides a set of hierarchical controlled vocabulary split into 3 categories:<p><a href='/help/gene_ontology' target='_top'>More...</a></p>GO - Molecular functioni

<p>UniProtKB Keywords constitute a <a href="http://www.uniprot.org/keywords">controlled vocabulary</a> with a hierarchical structure. Keywords summarise the content of a UniProtKB entry and facilitate the search for proteins of interest.<p><a href='/help/keywords' target='_top'>More...</a></p>Keywordsi

Molecular functionIon channel impairing toxin, Neurotoxin, Potassium channel impairing toxin, Toxin, Voltage-gated potassium channel impairing toxin

<p>This section provides information about the protein and gene name(s) and synonym(s) and about the organism that is the source of the protein sequence.<p><a href='/help/names_and_taxonomy_section' target='_top'>More...</a></p>Names & Taxonomyi

<p>This subsection of the <a href="http://www.uniprot.org/help/names_and_taxonomy_section">Names and taxonomy</a> section provides an exhaustive list of all names of the protein, from commonly used to obsolete, to allow unambiguous identification of a protein.<p><a href='/help/protein_names' target='_top'>More...</a></p>Protein namesi
Recommended name:
Potassium channel toxin gamma-KTx 2.11 Publication
Alternative name(s):
Neurotoxin BeKm-11 Publication
Short name:
BeKm1Curated
<p>This subsection of the <a href="http://www.uniprot.org/help/names_and_taxonomy_section">Names and taxonomy</a> section provides information on the name(s) of the organism that is the source of the protein sequence.<p><a href='/help/organism-name' target='_top'>More...</a></p>OrganismiMesobuthus eupeus (Lesser Asian scorpion) (Buthus eupeus)
<p>This subsection of the <a href="http://www.uniprot.org/help/names_and_taxonomy_section">Names and taxonomy</a> section shows the unique identifier assigned by the NCBI to the source organism of the protein. This is known as the ‘taxonomic identifier’ or ‘taxid’.<p><a href='/help/taxonomic_identifier' target='_top'>More...</a></p>Taxonomic identifieri34648 [NCBI]
<p>This subsection of the <a href="http://www.uniprot.org/help/names_and_taxonomy_section">Names and taxonomy</a> section contains the taxonomic hierarchical classification lineage of the source organism. It lists the nodes as they appear top-down in the taxonomic tree, with the more general grouping listed first.<p><a href='/help/taxonomic_lineage' target='_top'>More...</a></p>Taxonomic lineageiEukaryotaMetazoaEcdysozoaArthropodaChelicerataArachnidaScorpionesButhidaButhoideaButhidaeMesobuthus

<p>This section provides information on the location and the topology of the mature protein in the cell.<p><a href='/help/subcellular_location_section' target='_top'>More...</a></p>Subcellular locationi

Extracellular region or secreted Cytosol Plasma membrane Cytoskeleton Lysosome Endosome Peroxisome ER Golgi apparatus Nucleus Mitochondrion Manual annotation Automatic computational assertionGraphics by Christian Stolte; Source: COMPARTMENTS

Keywords - Cellular componenti

Secreted

<p>This section provides information on the disease(s) and phenotype(s) associated with a protein.<p><a href='/help/pathology_and_biotech_section' target='_top'>More...</a></p>Pathology & Biotechi

Mutagenesis

Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection of the <a href="http://www.uniprot.org/manual/pathology_and_biotech_section">'Pathology and Biotech'</a> section describes the effect of the experimental mutation of one or more amino acid(s) on the biological properties of the protein.<p><a href='/help/mutagen' target='_top'>More...</a></p>Mutagenesisi22R → A: 6.7-fold decrease in affinity to Kv11/ERG potassium channels. 1 Publication1
Mutagenesisi23P → A: 1.7-fold decrease in affinity to Kv11/ERG potassium channels. 1 Publication1
Mutagenesisi25D → A: 3.4-fold decrease in affinity to Kv11/ERG potassium channels. 1 Publication1
Mutagenesisi27K → A: 2.7-fold decrease in affinity to Kv11/ERG potassium channels. 1 Publication1
Mutagenesisi30E → A: 0.8-fold decrease in affinity to Kv11/ERG potassium channels. 1 Publication1
Mutagenesisi32Y → A: 14.7-fold decrease in affinity to Kv11/ERG potassium channels. 1 Publication1
Mutagenesisi33Q → A: 2.3-fold decrease in affinity to Kv11/ERG potassium channels. 1 Publication1
Mutagenesisi35F → A: 8.2-fold decrease in affinity to Kv11/ERG potassium channels. 1 Publication1
Mutagenesisi39K → A: 86.4-fold decrease in affinity to Kv11/ERG potassium channels. 1 Publication1
Mutagenesisi41R → A: 70.6-fold decrease in affinity to Kv11/ERG potassium channels. 1 Publication1
Mutagenesisi42F → A: 52.2-fold decrease in affinity to Kv11/ERG potassium channels. 1 Publication1
Mutagenesisi44K → A: 14.6-fold decrease in affinity to Kv11/ERG potassium channels. 1 Publication1
Mutagenesisi48R → A: 7.4-fold decrease in affinity to Kv11/ERG potassium channels. 1
Mutagenesisi48R → K: 60% loss of toxicity. No loss of activity; when associated with K-53. 2 Publications1
Mutagenesisi50V → A: 1.2-fold decrease in affinity to ERG-potassium channels. 1 Publication1
Mutagenesisi53F → A: 1.4-fold decrease in affinity to ERG-potassium channels. 2 Publications1
Mutagenesisi53F → K: No loss of activity. No loss of activity but gain in inhibition of native calcium- activated potassium channels with Kd of about 72 nM; when associated with K-48. 2 Publications1
Mutagenesisi55D → A: 1.1-fold decrease in affinity to Kv11/ERG potassium channels. 1 Publication1
Mutagenesisi57F → A: 3.2-fold decrease in affinity to Kv11/ERG potassium channels. 1 Publication1

<p>This section describes post-translational modifications (PTMs) and/or processing events.<p><a href='/help/ptm_processing_section' target='_top'>More...</a></p>PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection of the ‘PTM / Processing’ section denotes the presence of an N-terminal signal peptide.<p><a href='/help/signal' target='_top'>More...</a></p>Signal peptidei1 – 211 PublicationAdd BLAST21
<p>This subsection of the ‘PTM / Processing’ section describes the extent of a polypeptide chain in the mature protein following processing.<p><a href='/help/chain' target='_top'>More...</a></p>ChainiPRO_000003531322 – 57Potassium channel toxin gamma-KTx 2.11 PublicationAdd BLAST36

Amino acid modifications

Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection of the PTM / Processing":/help/ptm_processing_section section describes the positions of cysteine residues participating in disulfide bonds.<p><a href='/help/disulfid' target='_top'>More...</a></p>Disulfide bondi28 ↔ 491 Publication
Disulfide bondi34 ↔ 541 Publication
Disulfide bondi38 ↔ 561 Publication

Keywords - PTMi

Disulfide bond

<p>This section provides information on the expression of a gene at the mRNA or protein level in cells or in tissues of multicellular organisms.<p><a href='/help/expression_section' target='_top'>More...</a></p>Expressioni

<p>This subsection of the ‘Expression’ section provides information on the expression of a gene at the mRNA or protein level in cells or in tissues of multicellular organisms. By default, the information is derived from experiments at the mRNA level, unless specified ‘at protein level’. <br></br>Examples: <a href="http://www.uniprot.org/uniprot/P92958#expression">P92958</a>, <a href="http://www.uniprot.org/uniprot/Q8TDN4#expression">Q8TDN4</a>, <a href="http://www.uniprot.org/uniprot/O14734#expression">O14734</a><p><a href='/help/tissue_specificity' target='_top'>More...</a></p>Tissue specificityi

Expressed by the venom gland.Curated

<p>This section provides information on the tertiary and secondary structure of a protein.<p><a href='/help/structure_section' target='_top'>More...</a></p>Structurei

Secondary structure

157
Legend: HelixTurnBeta strandPDB Structure known for this area
Show more details

3D structure databases

Select the link destinations:

Protein Data Bank Europe

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PDBei

Protein Data Bank RCSB

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RCSB PDBi

Protein Data Bank Japan

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PDBji
Links Updated
PDB entryMethodResolution (Å)ChainPositionsPDBsum
1J5JNMR-A22-57[»]
1LGLNMR-A22-57[»]

Protein Model Portal of the PSI-Nature Structural Biology Knowledgebase

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ProteinModelPortali
Q9BKB7

SWISS-MODEL Repository - a database of annotated 3D protein structure models

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SMRi
Q9BKB7

Database of comparative protein structure models

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ModBasei
Search...

MobiDB: a database of protein disorder and mobility annotations

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MobiDBi
Search...

Miscellaneous databases

Relative evolutionary importance of amino acids within a protein sequence

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EvolutionaryTracei
Q9BKB7

<p>This section provides information on sequence similarities with other proteins and the domain(s) present in a protein.<p><a href='/help/family_and_domains_section' target='_top'>More...</a></p>Family & Domainsi

<p>This subsection of the ‘Family and domains’ section provides general information on the biological role of a domain. The term ‘domain’ is intended here in its wide acceptation, it may be a structural domain, a transmembrane region or a functional domain. Several domains are described in this subsection.<p><a href='/help/domain_cc' target='_top'>More...</a></p>Domaini

Has the CSalpha/beta fold, which comprises one or two short alpha helices connected to anti-parallel beta-sheets stabilized by three or four disulfide bonds.1 Publication

<p>This subsection of the ‘Family and domains’ section provides information about the sequence similarity with other proteins.<p><a href='/help/sequence_similarities' target='_top'>More...</a></p>Sequence similaritiesi

Keywords - Domaini

Signal

Family and domain databases

Gene3D Structural and Functional Annotation of Protein Families

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Gene3Di
3.30.30.10, 1 hit

Integrated resource of protein families, domains and functional sites

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InterProi
View protein in InterPro
IPR036574 Scorpion_toxin-like_sf
IPR001947 Scorpion_toxinS_K_inh

Pfam protein domain database

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Pfami
View protein in Pfam
PF00451 Toxin_2, 1 hit

ProDom; a protein domain database

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ProDomi
View protein in ProDom or Entries sharing at least one domain
PD003586 Scorpion_toxinS, 1 hit

Superfamily database of structural and functional annotation

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SUPFAMi
SSF57095 SSF57095, 1 hit

<p>This section displays by default the canonical protein sequence and upon request all isoforms described in the entry. It also includes information pertinent to the sequence(s), including <a href="http://www.uniprot.org/help/sequence_length">length</a> and <a href="http://www.uniprot.org/help/sequences">molecular weight</a>.<p><a href='/help/sequences_section' target='_top'>More...</a></p>Sequencei

<p>This subsection of the <a href="http://www.uniprot.org/help/sequences_section">Sequence</a> section indicates if the <a href="http://www.uniprot.org/help/canonical_and_isoforms">canonical sequence</a> displayed by default in the entry is complete or not.<p><a href='/help/sequence_status' target='_top'>More...</a></p>Sequence statusi: Complete.

<p>This subsection of the <a href="http://www.uniprot.org/help/sequences_section">Sequence</a> section indicates if the <a href="http://www.uniprot.org/help/canonical_and_isoforms">canonical sequence</a> displayed by default in the entry is in its mature form or if it represents the precursor.<p><a href='/help/sequence_processing' target='_top'>More...</a></p>Sequence processingi: The displayed sequence is further processed into a mature form.

Q9BKB7-1 [UniParc]FASTAAdd to basket
« Hide
        10         20         30         40         50
MKISFVLLLT LFICSIGWSE ARPTDIKCSE SYQCFPVCKS RFGKTNGRCV

NGFCDCF
Length:57
Mass (Da):6,452
Last modified:June 1, 2001 - v1
<p>The checksum is a form of redundancy check that is calculated from the sequence. It is useful for tracking sequence updates.</p> <p>It should be noted that while, in theory, two different sequences could have the same checksum value, the likelihood that this would happen is extremely low.</p> <p>However UniProtKB may contain entries with identical sequences in case of multiple genes (paralogs).</p> <p>The checksum is computed as the sequence 64-bit Cyclic Redundancy Check value (CRC64) using the generator polynomial: x<sup>64</sup> + x<sup>4</sup> + x<sup>3</sup> + x + 1. The algorithm is described in the ISO 3309 standard. </p> <p class="publication">Press W.H., Flannery B.P., Teukolsky S.A. and Vetterling W.T.<br /> <strong>Cyclic redundancy and other checksums</strong><br /> <a href="http://www.nrbook.com/b/bookcpdf.php">Numerical recipes in C 2nd ed., pp896-902, Cambridge University Press (1993)</a>)</p> Checksum:i8B85BF8660816666
GO

Sequence databases

Select the link destinations:

EMBL nucleotide sequence database

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EMBLi

GenBank nucleotide sequence database

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GenBanki

DNA Data Bank of Japan; a nucleotide sequence database

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DDBJi
Links Updated
AF276623 mRNA Translation: AAK28021.1

<p>This section provides links to proteins that are similar to the protein sequence(s) described in this entry at different levels of sequence identity thresholds (100%, 90% and 50%) based on their membership in UniProt Reference Clusters (<a href="http://www.uniprot.org/help/uniref">UniRef</a>).<p><a href='/help/similar_proteins_section' target='_top'>More...</a></p>Similar proteinsi

<p>This section is used to point to information related to entries and found in data collections other than UniProtKB.<p><a href='/help/cross_references_section' target='_top'>More...</a></p>Cross-referencesi

<p>This subsection of the <a href="http://www.uniprot.org/manual/cross_references_section">Cross-references</a> section provides links to various web resources that are relevant for a specific protein.<p><a href='/help/web_resource' target='_top'>More...</a></p>Web resourcesi

Biological Magnetic Resonance Data Bank

recombinant BeKm-1

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
AF276623 mRNA Translation: AAK28021.1

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
PDB entryMethodResolution (Å)ChainPositionsPDBsum
1J5JNMR-A22-57[»]
1LGLNMR-A22-57[»]
ProteinModelPortaliQ9BKB7
SMRiQ9BKB7
ModBaseiSearch...
MobiDBiSearch...

Protocols and materials databases

Structural Biology KnowledgebaseSearch...

Miscellaneous databases

EvolutionaryTraceiQ9BKB7

Family and domain databases

Gene3Di3.30.30.10, 1 hit
InterProiView protein in InterPro
IPR036574 Scorpion_toxin-like_sf
IPR001947 Scorpion_toxinS_K_inh
PfamiView protein in Pfam
PF00451 Toxin_2, 1 hit
ProDomiView protein in ProDom or Entries sharing at least one domain
PD003586 Scorpion_toxinS, 1 hit
SUPFAMiSSF57095 SSF57095, 1 hit

ProtoNet; Automatic hierarchical classification of proteins

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ProtoNeti
Search...

<p>This section provides general information on the entry.<p><a href='/help/entry_information_section' target='_top'>More...</a></p>Entry informationi

<p>This subsection of the ‘Entry information’ section provides a mnemonic identifier for a UniProtKB entry, but it is not a stable identifier. Each reviewed entry is assigned a unique entry name upon integration into UniProtKB/Swiss-Prot.<p><a href='/help/entry_name' target='_top'>More...</a></p>Entry nameiKGX21_MESEU
<p>This subsection of the ‘Entry information’ section provides one or more accession number(s). These are stable identifiers and should be used to cite UniProtKB entries. Upon integration into UniProtKB, each entry is assigned a unique accession number, which is called ‘Primary (citable) accession number’.<p><a href='/help/accession_numbers' target='_top'>More...</a></p>AccessioniPrimary (citable) accession number: Q9BKB7
<p>This subsection of the ‘Entry information’ section shows the date of integration of the entry into UniProtKB, the date of the last sequence update and the date of the last annotation modification (‘Last modified’). The version number for both the entry and the <a href="http://www.uniprot.org/help/canonical_and_isoforms">canonical sequence</a> are also displayed.<p><a href='/help/entry_history' target='_top'>More...</a></p>Entry historyiIntegrated into UniProtKB/Swiss-Prot: October 31, 2003
Last sequence update: June 1, 2001
Last modified: November 22, 2017
This is version 75 of the entry and version 1 of the sequence. See complete history.
<p>This subsection of the ‘Entry information’ section indicates whether the entry has been manually annotated and reviewed by UniProtKB curators or not, in other words, if the entry belongs to the Swiss-Prot section of UniProtKB (<strong>reviewed</strong>) or to the computer-annotated TrEMBL section (<strong>unreviewed</strong>).<p><a href='/help/entry_status' target='_top'>More...</a></p>Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programAnimal Toxin Annotation Program

<p>This section contains any relevant information that doesn’t fit in any other defined sections<p><a href='/help/miscellaneous_section' target='_top'>More...</a></p>Miscellaneousi

Keywords - Technical termi

3D-structure, Direct protein sequencing

Documents

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