ACTP5_ACTEQ
ID ACTP5_ACTEQ Reviewed; 214 AA.
AC Q93109;
DT 01-DEC-2000, integrated into UniProtKB/Swiss-Prot.
DT 01-FEB-1997, sequence version 1.
DT 03-AUG-2022, entry version 108.
DE RecName: Full=DELTA-actitoxin-Aeq1b {ECO:0000303|PubMed:22683676};
DE Short=DELTA-AITX-Aeq1b {ECO:0000303|PubMed:22683676};
DE AltName: Full=Equinatoxin V {ECO:0000303|PubMed:9357951};
DE Short=Eqt V;
DE Short=EqtV {ECO:0000303|PubMed:9357951};
DE AltName: Full=Equinatoxin-5 {ECO:0000305};
DE Flags: Precursor;
OS Actinia equina (Beadlet anemone).
OC Eukaryota; Metazoa; Cnidaria; Anthozoa; Hexacorallia; Actiniaria;
OC Actiniidae; Actinia.
OX NCBI_TaxID=6106;
RN [1]
RP NUCLEOTIDE SEQUENCE [MRNA].
RX PubMed=9357951; DOI=10.1016/s0167-4838(97)00083-6;
RA Pungercar J., Anderluh G., Macek P., Franc G., Strukelj B.;
RT "Sequence analysis of the cDNA encoding the precursor of equinatoxin V, a
RT newly discovered hemolysin from the sea anemone Actinia equina.";
RL Biochim. Biophys. Acta 1341:105-107(1997).
RN [2]
RP REVIEW.
RX PubMed=19268680; DOI=10.1016/j.toxicon.2009.02.026;
RA Kristan K.C., Viero G., Dalla Serra M., Macek P., Anderluh G.;
RT "Molecular mechanism of pore formation by actinoporins.";
RL Toxicon 54:1125-1134(2009).
RN [3]
RP NOMENCLATURE.
RX PubMed=22683676; DOI=10.1016/j.toxicon.2012.05.020;
RA Oliveira J.S., Fuentes-Silva D., King G.F.;
RT "Development of a rational nomenclature for naming peptide and protein
RT toxins from sea anemones.";
RL Toxicon 60:539-550(2012).
CC -!- FUNCTION: Pore-forming protein that forms cations-selective hydrophilic
CC pores of around 1 nm and causes hemolysis. Pore formation is a multi-
CC step process that involves specific recognition of membrane
CC sphingomyelin (but neither cholesterol nor phosphatidylcholine) using
CC aromatic rich region and adjacent phosphocholine (POC) binding site,
CC firm binding to the membrane (mainly driven by hydrophobic
CC interactions) accompanied by the transfer of the N-terminal region to
CC the lipid-water interface and finally pore formation after
CC oligomerization of monomers.
CC -!- SUBUNIT: Tetramer in the presence of a lipidic interface. Monomer, in
CC soluble state. {ECO:0000250}.
CC -!- SUBCELLULAR LOCATION: Secreted {ECO:0000305}. Nematocyst {ECO:0000305}.
CC Target cell membrane. Note=Forms an alpha-helical membrane channel in
CC the prey.
CC -!- DOMAIN: The N-terminal region, before the pore is formed, is bound to
CC the lipid membrane. It partitions into the lipid-water interface and
CC stabilizes the monomeric molecule on the membrane. Finally, it
CC traverses the bilayer, thus forming the transmembrane pore.
CC {ECO:0000250|UniProtKB:P61914}.
CC -!- SIMILARITY: Belongs to the actinoporin family. Sea anemone subfamily.
CC {ECO:0000305}.
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DR EMBL; U51900; AAC05720.1; -; mRNA.
DR AlphaFoldDB; Q93109; -.
DR SMR; Q93109; -.
DR TCDB; 1.C.38.1.9; the pore-forming equinatoxin (equinatoxin) family.
DR EnsemblMetazoa; EGACTEQ4350002124-RA; EGACTEQ4350002124-PA; EGACTEQ4350002124.
DR GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR GO; GO:0042151; C:nematocyst; IEA:UniProtKB-SubCell.
DR GO; GO:0046930; C:pore complex; IEA:InterPro.
DR GO; GO:0015267; F:channel activity; IEA:InterPro.
DR GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR GO; GO:0006812; P:cation transport; IEA:InterPro.
DR GO; GO:0044179; P:hemolysis in another organism; IEA:UniProtKB-KW.
DR GO; GO:0046931; P:pore complex assembly; IEA:InterPro.
DR Gene3D; 2.60.270.20; -; 1.
DR InterPro; IPR009104; Anemon_actinoporin-like.
DR InterPro; IPR015926; Cytolysin/lectin.
DR Pfam; PF06369; Anemone_cytotox; 1.
DR SUPFAM; SSF63724; SSF63724; 1.
PE 2: Evidence at transcript level;
KW Cleavage on pair of basic residues; Cytolysis; Hemolysis; Ion transport;
KW Membrane; Nematocyst; Secreted; Signal; Target cell membrane;
KW Target membrane; Toxin; Transmembrane; Transport.
FT SIGNAL 1..19
FT /evidence="ECO:0000255"
FT PROPEP 20..35
FT /evidence="ECO:0000250"
FT /id="PRO_0000034834"
FT CHAIN 36..214
FT /note="DELTA-actitoxin-Aeq1b"
FT /id="PRO_0000034835"
FT REGION 38..47
FT /note="Plays an important role in the hemolytic activity"
FT /evidence="ECO:0000250|UniProtKB:P07845"
FT REGION 46..65
FT /note="N-terminal region"
FT /evidence="ECO:0000250|UniProtKB:P61914"
FT REGION 140..155
FT /note="Trp-rich region, which is important for the binding
FT to lipid membrane"
FT /evidence="ECO:0000250|UniProtKB:P61914"
FT MOTIF 179..181
FT /note="Cell attachment site"
FT /evidence="ECO:0000255"
FT BINDING 89
FT /ligand="phosphocholine"
FT /ligand_id="ChEBI:CHEBI:295975"
FT /evidence="ECO:0000250|UniProtKB:P07845"
FT BINDING 122
FT /ligand="phosphocholine"
FT /ligand_id="ChEBI:CHEBI:295975"
FT /evidence="ECO:0000250|UniProtKB:P07845"
FT BINDING 140
FT /ligand="phosphocholine"
FT /ligand_id="ChEBI:CHEBI:295975"
FT /evidence="ECO:0000250|UniProtKB:P07845"
FT BINDING 142
FT /ligand="phosphocholine"
FT /ligand_id="ChEBI:CHEBI:295975"
FT /evidence="ECO:0000250|UniProtKB:P07845"
FT BINDING 168
FT /ligand="phosphocholine"
FT /ligand_id="ChEBI:CHEBI:295975"
FT /evidence="ECO:0000250|UniProtKB:P07845"
FT BINDING 172
FT /ligand="phosphocholine"
FT /ligand_id="ChEBI:CHEBI:295975"
FT /evidence="ECO:0000250|UniProtKB:P07845"
FT BINDING 173
FT /ligand="phosphocholine"
FT /ligand_id="ChEBI:CHEBI:295975"
FT /evidence="ECO:0000250|UniProtKB:P07845"
FT SITE 148
FT /note="Important in the initial contact with the lipid
FT membrane"
FT /evidence="ECO:0000250|UniProtKB:P61914"
FT SITE 179
FT /note="Interacts with the lipid membrane"
FT /evidence="ECO:0000250|UniProtKB:P61914"
SQ SEQUENCE 214 AA; 23617 MW; 9332D0FBBF23827B CRC64;
MSRLIIVFIV VTMICAATAL SSKKSINEDE KDEKRSVAVA GAVIEGATLT FNVLQTVLKA
LGDISRKIAV GIDNESGMTW TAMNTYFRSG TSDVILPHTV PHGKALLYNG QKDRGPVATG
VVGVLAYAMS DGNTLAVLFS IPFDYNLYSN WWNVKVYKGH RRADQRMYEE LYYNLSPFRG
DNGWHNRDLG YGLKGRGFMN SSGQSILEIH VTKA
