ACTP4_HETMG
ID ACTP4_HETMG Reviewed; 177 AA.
AC P0DMX2;
DT 22-JUL-2015, integrated into UniProtKB/Swiss-Prot.
DT 22-JUL-2015, sequence version 1.
DT 25-MAY-2022, entry version 17.
DE RecName: Full=DELTA-stichotoxin-Hmg2b {ECO:0000303|PubMed:22683676};
DE Short=DELTA-SHTX-Hmg2b {ECO:0000303|PubMed:22683676};
DE AltName: Full=Cytolysin HmT {ECO:0000303|PubMed:10665806};
DE AltName: Full=Hemolytic protein {ECO:0000303|PubMed:10665806};
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, AND FUNCTION.
RX PubMed=10665806; DOI=10.1016/s0041-0101(99)00154-3;
RA Samejima Y., Yanagisawa M., Aoki-Tomomatsu Y., Iwasaki E., Ando J.,
RA Mebs D.;
RT "Amino acid sequence studies on cytolytic toxins from sea anemone
RT Heteractis magnifica, Entacmaea quadricolor and Stichodactyla mertensii
RT (Anthozoa).";
RL Toxicon 38:259-264(2000).
RN [2]
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).
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 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 (By similarity) This toxin shows hemolytic
CC activity (PubMed:10665806). {ECO:0000250|UniProtKB:P39088,
CC ECO:0000269|PubMed:10665806}.
CC -!- SUBUNIT: Tetramer in the presence of a lipidic interface. Monomer, in
CC soluble state. {ECO:0000250}.
CC -!- SUBCELLULAR LOCATION: Secreted {ECO:0000250|UniProtKB:P39088}.
CC Nematocyst {ECO:0000250|UniProtKB:P39088}. Target cell membrane
CC {ECO:0000250|UniProtKB:P39088}. Note=Forms an alpha-helical membrane
CC channel in the prey. {ECO:0000250|UniProtKB:P39088}.
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 AlphaFoldDB; P0DMX2; -.
DR SMR; P0DMX2; -.
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..177
FT /note="DELTA-stichotoxin-Hmg2b"
FT /evidence="ECO:0000269|PubMed:10665806"
FT /id="PRO_0000433581"
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 SITE 113
FT /note="Important in the initial contact with the lipid
FT membrane"
FT /evidence="ECO:0000250|UniProtKB:P61914"
SQ SEQUENCE 177 AA; 19204 MW; 351D3BC3BC832F35 CRC64;
SAALAGTIIA GASLGFQILD KVLGELGKVS RKIAIGVDNE SGGSTTALNA YFRSGTGDVI
LPEFVPNQKA LLYSGRKDTG PVATGAVAAF AYYMSNGHTL GVMFSVPFDY NFYSNWWDVK
VYSGKRRADQ GMYEDMYYGN PYRGDNGWHQ KNLGYGLRMK GIMTSAGEAI LQIKISR
