ACTPB_ACTTE
ID ACTPB_ACTTE Reviewed; 214 AA.
AC P30834; A0A6P8I7C5;
DT 01-JUL-1993, integrated into UniProtKB/Swiss-Prot.
DT 02-JUN-2021, sequence version 2.
DT 03-AUG-2022, entry version 74.
DE RecName: Full=Cytolysin tenebrosin-B {ECO:0000303|PubMed:1970442};
DE AltName: Full=DELTA-actitoxin {ECO:0000305};
DE Flags: Precursor;
OS Actinia tenebrosa (Australian red waratah sea anemone).
OC Eukaryota; Metazoa; Cnidaria; Anthozoa; Hexacorallia; Actiniaria;
OC Actiniidae; Actinia.
OX NCBI_TaxID=6105;
RN [1] {ECO:0000312|Proteomes:UP000515163}
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RX PubMed=31641475; DOI=10.1002/ece3.5633;
RA Surm J.M., Stewart Z.K., Papanicolaou A., Pavasovic A., Prentis P.J.;
RT "The draft genome of Actinia tenebrosa reveals insights into toxin
RT evolution.";
RL Ecol. Evol. 9:11314-11328(2019).
RN [2]
RP PROTEIN SEQUENCE OF 36-55.
RX PubMed=1970442; DOI=10.1016/0041-0101(90)90004-q;
RA Norton R.S., Bobek G., Ivanov J.O., Thomson M., Fiala-Beer E., Moritz R.L.,
RA Simpson R.J.;
RT "Purification and characterisation of proteins with cardiac stimulatory and
RT haemolytic activity from the anemone Actinia tenebrosa.";
RL Toxicon 28:29-41(1990).
RN [3]
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).
CC -!- FUNCTION: Pore-forming protein that forms cations-selective hydrophilic
CC pores of around 1 nm and causes cardiac stimulation and hemolysis. Pore
CC formation is a multi-step process that involves specific recognition of
CC membrane sphingomyelin (but neither cholesterol nor
CC phosphatidylcholine) using aromatic rich region and adjacent
CC phosphocholine (POC) binding site, firm binding to the membrane (mainly
CC driven by hydrophobic interactions) accompanied by the transfer of the
CC N-terminal region to the lipid-water interface and finally pore
CC formation after 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 PIR; B34016; B34016.
DR AlphaFoldDB; P30834; -.
DR SMR; P30834; -.
DR Proteomes; UP000515163; Unplaced.
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 1: Evidence at protein level;
KW Cleavage on pair of basic residues; Cytolysis; Direct protein sequencing;
KW Hemolysis; Ion transport; Membrane; Nematocyst; Reference proteome;
KW Secreted; Signal; Target cell membrane; Target membrane; Toxin;
KW Transmembrane; Transport.
FT SIGNAL 1..19
FT /evidence="ECO:0000255"
FT PROPEP 20..35
FT /evidence="ECO:0000305|PubMed:1970442"
FT /id="PRO_0000452708"
FT CHAIN 36..214
FT /note="Cytolysin tenebrosin-B"
FT /evidence="ECO:0000305|PubMed:1970442"
FT /id="PRO_0000221531"
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"
FT SITE 195
FT /note="Interacts with the lipid membrane"
FT /evidence="ECO:0000250|UniProtKB:P61914"
SQ SEQUENCE 214 AA; 23825 MW; FB5178854EC376E1 CRC64;
MNRLIIVFIV VTMICAATAL STKRRINKEE KDEKRSVAVA GAVIEGATLT FNVLQTVLKA
LGDISRKIAV GIDNESGMTW TAMNTYFRSG TSDIVLPYEV PHGKALLYNG QKDRGPVATG
VVGVLAYAMS DGNTLAVLFS IPFDYNLYSN WWNVKVYKGH RRADQRMYEE LYYNLSPFRG
DNGWHNRDLG YGLTSRGFMN SSGQSILEIH VTKA
