UniProtKB - P61914 (ACTP2_ACTEQ)
DELTA-actitoxin-Aeq1a
Functioni
Pore-forming protein that forms cations-selective hydrophilic pores of around 1 nm and causes cardiac stimulation and hemolysis. Pore formation is a multi-step process that involves specific recognition of membrane sphingomyelin (but neither cholesterol nor phosphatidylcholine) using aromatic rich region and adjacent phosphocholine (POC) binding site, firm binding to the membrane (mainly driven by hydrophobic interactions) accompanied by the transfer of the N-terminal region to the lipid-water interface and finally pore formation after oligomerization of monomers. Cytolytic effects include red blood cells hemolysis, platelet aggregation and lysis, cytotoxic and cytostatic effects on fibroblasts. Lethality in mammals has been ascribed to severe vasospasm of coronary vessels, cardiac arrhythmia, and inotropic effects.
Sites
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Binding sitei | 89 | PhosphocholineBy similarity | 1 | |
Binding sitei | 122 | PhosphocholineBy similarity | 1 | |
Binding sitei | 140 | PhosphocholineBy similarity | 1 | |
Binding sitei | 142 | PhosphocholineBy similarity | 1 | |
Sitei | 147 | Important in the initial contact with the lipid membrane1 Publication | 1 | |
Sitei | 148 | Important in the initial contact with the lipid membrane1 Publication | 1 | |
Binding sitei | 168 | PhosphocholineBy similarity | 1 | |
Binding sitei | 172 | PhosphocholineBy similarity | 1 | |
Binding sitei | 173 | PhosphocholineBy similarity | 1 | |
Sitei | 179 | Interacts with the lipid membrane1 Publication | 1 | |
Sitei | 195 | Interacts with the lipid membrane1 Publication | 1 |
GO - Molecular functioni
- channel activity Source: InterPro
- toxin activity Source: UniProtKB-KW
GO - Biological processi
- cation transport Source: InterPro
- hemolysis in another organism Source: UniProtKB-KW
- pore complex assembly Source: InterPro
Keywordsi
Molecular function | Toxin |
Biological process | Cytolysis, Hemolysis, Ion transport, Transport |
Names & Taxonomyi
Protein namesi | Recommended name: DELTA-actitoxin-Aeq1a1 PublicationShort name: DELTA-AITX-Aeq1a1 Publication Alternative name(s): Equinatoxin II1 Publication Short name: EqT II1 Publication Short name: EqTII1 Publication Equinatoxin-2Curated |
Organismi | Actinia equina (Beadlet anemone) |
Taxonomic identifieri | 6106 [NCBI] |
Taxonomic lineagei | Eukaryota › Metazoa › Cnidaria › Anthozoa › Hexacorallia › Actiniaria › Actiniidae › Actinia |
Subcellular locationi
Extracellular region or secreted
Other locations
Note: Forms an alpha-helical membrane channel in the prey.
Extracellular region or secreted
- extracellular region Source: UniProtKB-SubCell
Other locations
- nematocyst Source: UniProtKB-SubCell
- pore complex Source: InterPro
Keywords - Cellular componenti
Membrane, Nematocyst, Secreted, Target cell membrane, Target membranePathology & Biotechi
Toxic dosei
Mutagenesis
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Mutagenesisi | 80 | W → F: Expressed only 7% of the wild-type hemolytic activity. 1 Publication | 1 | |
Mutagenesisi | 147 | W → A: Inhibition of direct binding of sphingomyelin. 1 Publication | 1 | |
Mutagenesisi | 148 | Y → A: Inhibition of direct binding of sphingomyelin. 1 Publication | 1 | |
Mutagenesisi | 151 – 152 | WW → FF: Expressed only 31% of the wild-type hemolytic activity. 1 Publication | 2 | |
Mutagenesisi | 184 | W → F: Expressed only 2% of the wild-type hemolytic activity. 1 Publication | 1 |
PTM / Processingi
Molecule processing
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Signal peptidei | 1 – 19 | Sequence analysisAdd BLAST | 19 | |
PropeptideiPRO_0000034830 | 20 – 35 | 2 PublicationsAdd BLAST | 16 | |
ChainiPRO_0000034831 | 36 – 214 | DELTA-actitoxin-Aeq1a1 PublicationAdd BLAST | 179 |
Keywords - PTMi
Cleavage on pair of basic residuesInteractioni
Subunit structurei
Tetramer in the presence of a lipidic interface. Monomer, in soluble state.
Structurei
Secondary structure
3D structure databases
AlphaFoldDBi | P61914 |
BMRBi | P61914 |
SMRi | P61914 |
ModBasei | Search... |
PDBe-KBi | Search... |
Miscellaneous databases
EvolutionaryTracei | P61914 |
Family & Domainsi
Region
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Regioni | 38 – 47 | Plays an important role in the hemolytic activityBy similarity | 10 | |
Regioni | 46 – 65 | N-terminal region1 PublicationAdd BLAST | 20 | |
Regioni | 140 – 155 | Trp-rich region, which is important for the binding to lipid membrane1 PublicationAdd BLAST | 16 |
Motif
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Motifi | 179 – 181 | Cell attachment siteSequence analysis | 3 |
Domaini
Sequence similaritiesi
Keywords - Domaini
Signal, TransmembraneFamily and domain databases
Gene3Di | 2.60.270.20, 1 hit |
InterProi | View protein in InterPro IPR009104, Anemon_actinoporin-like IPR015926, Cytolysin/lectin |
Pfami | View protein in Pfam PF06369, Anemone_cytotox, 1 hit |
SUPFAMi | SSF63724, SSF63724, 1 hit |
i Sequence
Sequence statusi: Complete.
: The displayed sequence is further processed into a mature form. Sequence processingi
10 20 30 40 50
MSRLIIVFIV VTMICSATAL PSKKIIDEDE EDEKRSADVA GAVIDGASLS
60 70 80 90 100
FDILKTVLEA LGNVKRKIAV GVDNESGKTW TALNTYFRSG TSDIVLPHKV
110 120 130 140 150
PHGKALLYNG QKDRGPVATG AVGVLAYLMS DGNTLAVLFS VPYDYNWYSN
160 170 180 190 200
WWNVRIYKGK RRADQRMYEE LYYNLSPFRG DNGWHTRNLG YGLKSRGFMN
210
SSGHAILEIH VSKA
Natural variant
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Natural varianti | 116 | P → D. | 1 |
Sequence databases
Select the link destinations: EMBLi GenBanki DDBJi Links Updated | U41661 mRNA Translation: AAC47005.1 |
PIRi | JC4682 |
Genome annotation databases
EnsemblMetazoai | EGACTEQ4350043623-RA; EGACTEQ4350043623-PA; EGACTEQ4350043623 |
Similar proteinsi
Cross-referencesi
Sequence databases
Select the link destinations: EMBLi GenBanki DDBJi Links Updated | U41661 mRNA Translation: AAC47005.1 |
PIRi | JC4682 |
3D structure databases
Select the link destinations: PDBei RCSB PDBi PDBji Links Updated | PDB entry | Method | Resolution (Å) | Chain | Positions | PDBsum |
1IAZ | X-ray | 1.90 | A/B | 36-214 | [»] | |
1KD6 | NMR | - | A | 36-214 | [»] | |
1TZQ | X-ray | 2.30 | A | 40-214 | [»] | |
AlphaFoldDBi | P61914 | |||||
BMRBi | P61914 | |||||
SMRi | P61914 | |||||
ModBasei | Search... | |||||
PDBe-KBi | Search... |
Genome annotation databases
EnsemblMetazoai | EGACTEQ4350043623-RA; EGACTEQ4350043623-PA; EGACTEQ4350043623 |
Miscellaneous databases
EvolutionaryTracei | P61914 |
Family and domain databases
Gene3Di | 2.60.270.20, 1 hit |
InterProi | View protein in InterPro IPR009104, Anemon_actinoporin-like IPR015926, Cytolysin/lectin |
Pfami | View protein in Pfam PF06369, Anemone_cytotox, 1 hit |
SUPFAMi | SSF63724, SSF63724, 1 hit |
MobiDBi | Search... |
Entry informationi
Entry namei | ACTP2_ACTEQ | |
Accessioni | P61914Primary (citable) accession number: P61914 Secondary accession number(s): P17723 Q9TWV3 | |
Entry historyi | Integrated into UniProtKB/Swiss-Prot: | June 7, 2004 |
Last sequence update: | June 7, 2004 | |
Last modified: | May 25, 2022 | |
This is version 96 of the entry and version 1 of the sequence. See complete history. | ||
Entry statusi | Reviewed (UniProtKB/Swiss-Prot) | |
Annotation program | Animal Toxin Annotation Program |
Miscellaneousi
Keywords - Technical termi
3D-structure, Direct protein sequencingDocuments
- PDB cross-references
Index of Protein Data Bank (PDB) cross-references - SIMILARITY comments
Index of protein domains and families