ID   ACTPH_HETMG             Reviewed;          54 AA.
AC   P39088;
DT   01-FEB-1995, integrated into UniProtKB/Swiss-Prot.
DT   01-FEB-1995, sequence version 1.
DT   25-MAY-2022, entry version 87.
DE   RecName: Full=Hemolytic toxin;
DE   AltName: Full=Cytolysin;
DE   AltName: Full=DELTA-stichotoxin {ECO:0000305};
DE   Flags: Fragment;
OS   Heteractis magnifica (Magnificent sea anemone) (Radianthus magnifica).
OC   Eukaryota; Metazoa; Cnidaria; Anthozoa; Hexacorallia; Actiniaria;
OC   Stichodactylidae; Heteractis.
OX   NCBI_TaxID=38281;
RN   [1]
RP   PROTEIN SEQUENCE.
RA   Mebs D., Claus I., Schroeter A., Takeya H., Iwanaga S.;
RL   (In) Gopalakrishnakone P., Tan C.K. (eds.);
RL   Recent advances in toxinology research, pp.2:392-395, National University
RL   of Singapore, Singapore (1992).
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).
CC   -!- FUNCTION: Pore-forming protein that forms cations-selective hydrophilic
CC       pores of around 1 nm and causes cytolysis and hemolysis. Pore formation
CC       is a multi-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 (By similarity). {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: Secreted. Nematocyst. Target cell membrane.
CC       Note=Forms an alpha-helical membrane channel in 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   TCDB; 1.C.38.1.6; the pore-forming equinatoxin (equinatoxin) family.
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   Cytolysis; Direct protein sequencing; Hemolysis; Ion transport; Membrane;
KW   Nematocyst; Secreted; Target cell membrane; Target membrane; Toxin;
KW   Transmembrane; Transport.
FT   CHAIN           1..>54
FT                   /note="Hemolytic toxin"
FT                   /id="PRO_0000221536"
FT   REGION          3..12
FT                   /note="Plays an important role in the hemolytic activity"
FT                   /evidence="ECO:0000250|UniProtKB:P07845"
FT   REGION          11..30
FT                   /note="N-terminal region"
FT                   /evidence="ECO:0000250|UniProtKB:P61914"
FT   NON_TER         54
SQ   SEQUENCE   54 AA;  5546 MW;  11E9EFCC1504BA27 CRC64;
     SAALAGTIIA GASLGFQILD KVLGELGKVS RKIAIGVDNE SIGSNTAWTX XXXW