Skip Header

You are using a version of browser that may not display all the features of this website. Please consider upgrading your browser.
Entry version 115 (02 Jun 2021)
Sequence version 1 (01 Dec 1992)
Previous versions | rss
Add a publicationFeedback


Stichodactyla helianthus (Sun anemone) (Stoichactis helianthus)
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

Peptide with both antimicrobial and neurotoxin activities. Inhibits voltage-dependent potassium channels. Potently blocks Kv1.1/KCNA1 (IC50=6.7-87 pM) and Kv1.3/KCNA3 (IC50=10-250 pM) (PubMed:8567178, PubMed:15665253, PubMed:9830012, PubMed:10545177, PubMed:23919482, PubMed:26288216, PubMed:28194851).

Less potently blocks Kv1.4/KCNA4 (IC50=0.31 nM), and Kv1.6/KCNA6 (IC50=0.16 nM) (PubMed:9830012).

Shows moderate activity on Kv1.2/KCNA2 (IC50=9 nM), Kv1.7/KCNA7 (IC50=11.5 nM), and KCa3.1/KCNN4 (Kd=0.03-30 nM) (PubMed:10419508, PubMed:9830012).

Blocks Kv channels by binding to a shallow vestibule at the outer entrance to the ion conduction pathway and occluding the entrance to the pore (PubMed:10419508, PubMed:9830012).

Shows antibacterial activity against all tested bacteria (the Gram-positive bacteria B.subtilis and S.aureus, and the Gram-negative bacteria S.typhimurium and P.aeruginosa) (PubMed:28796463).

9 Publications


Does not show or very weak activity on Kv1.5/KCNA5, Kv3.1/KCNC1, and Kv3.4/KCNC4 (IC50>100 nM).1 Publication
The synthetic analog ShK-192 has a paraphosphono-Phe (Ppa) at position 0, a Norleucine at position 21, and is amidated. It is stable at acidic pH values and high temperatures. The circulating half-life of the synthetic mutant is estimated to be about 30 minutes in rats. However, low concentrations of functionally active peptide are detected in the blood 72 hours after the injection. The synthetic mutant effectively inhibits the proliferation of T lymphocytes (T(EM)) cells in rats and suppresses delayed type hypersensitivity when administered at 10 or 100 µg/kg by subcutaneous injection once daily.1 Publication
The synthetic analog ShK-145 has a 20 kDa polyethylene glycol (PEG), and a Lys at position 16. In vivo, its injection into rat model of multiple sclerosis inhibits the progression of the disease. In addition, weekly administration of ShK-145 suppress interleukin-17 (IL-17) cytokine secretion from T cells in cynomolgus monkeys and does not show adverse side effects.1 Publication
The synthetic analog ShK-L5 contains a L-phosphotyrosine linked via a hydrophilic linker to the N-terminus of the ShK peptide. It is a highly specific Kv1.3/KCNA3 blocker that exhibits 100-fold selectivity for Kv1.3/KCNA3 over Kv1.1/KCNA1 and greater than 250-fold selectivity over all other channels tested. In vivo, it does not cause cardiac toxicity and does not alter clinical chemistry and hematological parameters after 2-week therapy. It also prevents and treats experimental autoimmune encephalomyelitis and suppresses delayed type hypersensitivity in rats.1 Publication


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>Sitei7Important residue for binding Kv1.3/KCNA31 Publication1
Sitei9Important residue for binding Kv1.3/KCNA31 Publication1
Sitei11Important residue for binding Kv1.3/KCNA32 Publications1
Sitei20Important residue for binding Kv1.3/KCNA31 Publication1
Sitei21Important residue for binding Kv1.3/KCNA31 Publication1
Sitei22Key residue for binding both Kv1.2/KCNA2 and Kv1.3/KCNA3 (occludes the channel pore like a cork in a bottle)2 Publications1
Sitei23Important residue for binding Kv1.3/KCNA31 Publication1
Sitei27Important residue for binding Kv1.3/KCNA31 Publication1

<p>The <a href="">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

GO - Biological processi

<p>UniProtKB Keywords constitute a <a href="">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 functionAntibiotic, Antimicrobial, Ion channel impairing toxin, Neurotoxin, Potassium channel impairing toxin, Toxin, Voltage-gated potassium channel impairing toxin

Protein family/group databases

Transport Classification Database

8.B.14.1.2, the sea anemone peptide toxin, class 1 (bgk) family

<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="">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:
Kappa-stichotoxin-She3a1 Publication
Short name:
Kappa-SHTX-She3a1 Publication
Alternative name(s):
Potassium channel toxin ShK1 Publication
<p>This subsection of the <a href="">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>OrganismiStichodactyla helianthus (Sun anemone) (Stoichactis helianthus)
<p>This subsection of the <a href="">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 identifieri6123 [NCBI]
<p>This subsection of the <a href="">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 lineageiEukaryotaMetazoaCnidariaAnthozoaHexacoralliaActiniariaStichodactylidaeStichodactyla

<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

Keywords - Cellular componenti

Nematocyst, 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

<p>This subsection of the 'Pathology and Biotech' section describes the use of a protein as a pharmaceutical drug. It indicates the name of the drug, the name of the firm that commercializes it and explains in a few words in which context the drug is used. In some cases, drugs that are under development are also described.<p><a href='/help/pharmaceutical_use' target='_top'>More...</a></p>Pharmaceutical usei

Synthetic analog ShK-186 is under clinical trial by 'Kv1.3 Therapeutics, Inc.' under the name dalazatide. Dalazatide has been validated in multiple models of autoimmune disease and has demonstrated proof of concept in a Phase 1b study in psoriasis. Dalazatide is ready to begin Phase 2 clinical studies for inclusion body myositis (IBM) a rare disease with no approved treatment options and generally poor prognosis for the patients. The dalazatide development program is focused on providing a breakthrough treatment first for IBM and then followed by other rare and autoimmune diseases. ShK-186 contains an L-phosphotyrosine attached via an aeea (mini-PEG) hydrophilic linker to Arg-1 and is amidated.2 Publications


Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection of the <a href="">'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>Mutagenesisi7I → Q: 10-fold decrease in potency of inhibition of Kv1.3/KCNA3. 1 Publication1
Mutagenesisi9K → Q: 10-fold decrease in potency of inhibition of Kv1.3/KCNA3. 1 Publication1
Mutagenesisi11R → Q: 7.5- to 42-fold decrease in potency of inhibition of Kv1.3/KCNA3. 2 Publications1
Mutagenesisi16Q → K: 6.6-fold increase in selectivity for Kv1.3/KCNA3 over Kv1.1/KCNA1, which is marked by a 2.6-fold and 117-fold decrease in potency of inhibition of Kv1.3/KCNA3 and Kv1.1/KCNA1, respectively. 1 Publication1
Mutagenesisi20S → A: 20-fold decrease in potency of inhibition of Kv1.3/KCNA3, and 80-fold decrease in potency of inhibition of KCa3.1/KCNN4. 1 Publication1
Mutagenesisi20S → Q or R: More than 25-fold decrease in potency of inhibition of Kv1.3/KCNA3. 1 Publication1
Mutagenesisi21M → Q: More than 25-fold decrease in potency of inhibition of Kv1.3/KCNA3. 1 Publication1
Mutagenesisi22K → Q or R: More than 25-fold decrease in potency of inhibition of Kv1.3/KCNA3. 2 Publications1
Mutagenesisi23Y → Q or R: More than 25-fold decrease in potency of inhibition of Kv1.3/KCNA3. 1 Publication1
Mutagenesisi27F → Q or R: More than 25-fold decrease in potency of inhibition of Kv1.3/KCNA3. 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 describes the position and length of an active peptide in the mature protein.<p><a href='/help/peptide' target='_top'>More...</a></p>PeptideiPRO_00000448661 – 35Kappa-stichotoxin-She3a2 PublicationsAdd BLAST35

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 bondi3 ↔ 354 PublicationsImported
Disulfide bondi12 ↔ 285 PublicationsImported
Disulfide bondi17 ↔ 325 PublicationsImported

Keywords - PTMi

Disulfide bond

<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

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

3D structure databases

Biological Magnetic Resonance Data Bank


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


Database of comparative protein structure models


Protein Data Bank in Europe - Knowledge Base


Miscellaneous databases

Relative evolutionary importance of amino acids within a protein sequence


<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

Domains and Repeats

Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection of the <a href="">Family and Domains</a> section describes the position and type of a domain, which is defined as a specific combination of secondary structures organized into a characteristic three-dimensional structure or fold.<p><a href='/help/domain' target='_top'>More...</a></p>Domaini3 – 35ShKTPROSITE-ProRule annotationAdd BLAST33

<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

Family and domain databases

Integrated resource of protein families, domains and functional sites

View protein in InterPro
IPR003582, ShKT_dom

PROSITE; a protein domain and family database

View protein in PROSITE
PS51670, SHKT, 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="">length</a> and <a href="">molecular weight</a>. The information is filed in different subsections. The current subsections and their content are listed below:<p><a href='/help/sequences_section' target='_top'>More...</a></p>Sequencei

<p>This subsection of the <a href="">Sequence</a> section indicates if the <a href="">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.

P29187-1 [UniParc]FASTAAdd to basket
« Hide
        10         20         30 
Mass (Da):4,061
Last modified:December 1, 1992 - 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="">Numerical recipes in C 2nd ed., pp896-902, Cambridge University Press (1993)</a>)</p> Checksum:iF53EF5D576734B6E

<p>This subsection of the 'Sequence' section reports information derived from mass spectrometry experiments done on the entire protein or on biologically active derived peptide(s).<p><a href='/help/mass_spectrometry' target='_top'>More...</a></p>Mass spectrometryi

Molecular mass is 4054.82±0.1 Da. Determined by ESI. 1 Publication

<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="">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

3D structure databases

Select the link destinations:

Protein Data Bank Europe


Protein Data Bank RCSB


Protein Data Bank Japan

Links Updated
PDB entryMethodResolution (Å)ChainPositionsPDBsum

Protein family/group databases

TCDBi8.B.14.1.2, the sea anemone peptide toxin, class 1 (bgk) family

Miscellaneous databases


Family and domain databases

InterProiView protein in InterPro
IPR003582, ShKT_dom
PROSITEiView protein in PROSITE
PS51670, SHKT, 1 hit

MobiDB: a database of protein disorder and mobility annotations


<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 nameiK1A_STIHL
<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: P29187
<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="">canonical sequence</a> are also displayed.<p><a href='/help/entry_history' target='_top'>More...</a></p>Entry historyiIntegrated into UniProtKB/Swiss-Prot: December 1, 1992
Last sequence update: December 1, 1992
Last modified: June 2, 2021
This is version 115 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, Pharmaceutical


  1. PDB cross-references
    Index of Protein Data Bank (PDB) cross-references
  2. SIMILARITY comments
    Index of protein domains and families
UniProt is an ELIXIR core data resource
Main funding by: National Institutes of Health

We'd like to inform you that we have updated our Privacy Notice to comply with Europe’s new General Data Protection Regulation (GDPR) that applies since 25 May 2018.

Do not show this banner again