ACTP2_MONPT
ID ACTP2_MONPT Reviewed; 275 AA.
AC Q76CA2;
DT 30-MAY-2006, integrated into UniProtKB/Swiss-Prot.
DT 27-JUL-2011, sequence version 2.
DT 03-AUG-2022, entry version 73.
DE RecName: Full=Echotoxin-2;
DE Short=Echt 2;
DE Flags: Precursor;
OS Monoplex parthenopeus (Giant triton) (Monoplex echo).
OC Eukaryota; Metazoa; Spiralia; Lophotrochozoa; Mollusca; Gastropoda;
OC Caenogastropoda; Littorinimorpha; Tonnoidea; Ranellidae; Monoplex.
OX NCBI_TaxID=230564;
RN [1]
RP NUCLEOTIDE SEQUENCE [MRNA], PROTEIN SEQUENCE OF 24-33; 84-100; 101-114;
RP 136-168 AND 169-189, AND MASS SPECTROMETRY.
RC TISSUE=Salivary gland;
RX PubMed=14529730; DOI=10.1016/s0041-0101(03)00226-5;
RA Kawashima Y., Nagai H., Ishida M., Nagashima Y., Shiomi K.;
RT "Primary structure of echotoxin 2, an actinoporin-like hemolytic toxin from
RT the salivary gland of the marine gastropod Monoplex echo.";
RL Toxicon 42:491-497(2003).
RN [2]
RP SEQUENCE REVISION TO 187-207.
RA Kawashima Y., Nagai H., Ishida M., Nagashima Y., Shiomi K.;
RL Submitted (SEP-2009) to the EMBL/GenBank/DDBJ databases.
RN [3]
RP AMINO-ACID COMPOSITION, AND FUNCTION.
RC TISSUE=Salivary gland;
RX PubMed=11821129; DOI=10.1016/s0041-0101(01)00256-2;
RA Shiomi K., Kawashima Y., Mizukami M., Nagashima Y.;
RT "Properties of proteinaceous toxins in the salivary gland of the marine
RT gastropod (Monoplex echo).";
RL Toxicon 40:563-571(2002).
RN [4]
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 (By similarity). Exhibits
CC both hemolytic and lethal activities. Gangliosides potently inhibits
CC the hemolytic activity. {ECO:0000250, ECO:0000269|PubMed:11821129}.
CC -!- SUBUNIT: Tetramer in the presence of a lipidic interface (By
CC similarity). Monomer. {ECO:0000250}.
CC -!- SUBCELLULAR LOCATION: Secreted. Target cell membrane {ECO:0000250}.
CC Note=Forms an alpha-helical membrane channel in the prey.
CC {ECO:0000250}.
CC -!- TISSUE SPECIFICITY: Salivary gland.
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 -!- MASS SPECTROMETRY: Mass=24135; Mass_error=19; Method=Electrospray;
CC Evidence={ECO:0000269|PubMed:14529730};
CC -!- MISCELLANEOUS: Is devoid of the RGD motif, but contains two Cys
CC residues.
CC -!- SIMILARITY: Belongs to the actinoporin family. Sea anemone subfamily.
CC {ECO:0000305}.
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DR EMBL; AB110013; BAD01578.2; -; mRNA.
DR AlphaFoldDB; Q76CA2; -.
DR SMR; Q76CA2; -.
DR TCDB; 1.C.38.1.5; the pore-forming equinatoxin (equinatoxin) family.
DR GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR GO; GO:0044179; P:hemolysis in another organism; IEA:UniProtKB-KW.
DR GO; GO:0006811; P:ion transport; IEA:UniProtKB-KW.
DR Gene3D; 2.60.270.20; -; 1.
DR InterPro; IPR015926; Cytolysin/lectin.
DR SUPFAM; SSF63724; SSF63724; 1.
PE 1: Evidence at protein level;
KW Cytolysis; Direct protein sequencing; Hemolysis; Ion transport; Membrane;
KW Secreted; Signal; Target cell membrane; Target membrane; Toxin;
KW Transmembrane; Transport.
FT SIGNAL 1..23
FT /evidence="ECO:0000269|PubMed:14529730"
FT CHAIN 24..248
FT /note="Echotoxin-2"
FT /id="PRO_0000239200"
FT PROPEP 249..275
FT /id="PRO_0000239201"
FT REGION 23..32
FT /note="Plays an important role in the hemolytic activity"
FT /evidence="ECO:0000250"
FT REGION 31..51
FT /note="N-terminal region"
FT /evidence="ECO:0000250"
FT REGION 61..78
FT /note="N-terminal region"
FT /evidence="ECO:0000250"
FT REGION 141..156
FT /note="Trp-rich region, which is important for the binding
FT to lipid membrane"
FT /evidence="ECO:0000250|UniProtKB:P61914"
FT BINDING 141
FT /ligand="phosphocholine"
FT /ligand_id="ChEBI:CHEBI:295975"
FT /evidence="ECO:0000250"
FT BINDING 143
FT /ligand="phosphocholine"
FT /ligand_id="ChEBI:CHEBI:295975"
FT /evidence="ECO:0000250"
FT BINDING 176
FT /ligand="phosphocholine"
FT /ligand_id="ChEBI:CHEBI:295975"
FT /evidence="ECO:0000250"
FT BINDING 177
FT /ligand="phosphocholine"
FT /ligand_id="ChEBI:CHEBI:295975"
FT /evidence="ECO:0000250"
FT SITE 149
FT /note="Important in the initial contact with the lipid
FT membrane"
FT /evidence="ECO:0000250"
SQ SEQUENCE 275 AA; 30112 MW; 7E78B5332AFB014E CRC64;
MKRNILALVV VVALISQSRP AESAGGTIIA TLSKIPLSTL ASALNTALET GASVASAAAA
ATSSDYSVTC VIEVENWTKH LMKYPVVQIA NSGGLLTVAK NVLPAEIQSF AMRKAWGANG
VYGTVSWVLG QTNRRVVIMW SAPYNFDFYS NWLAVGMSRP GLAVPSSRST WFDLMYYGNS
NADISFVRGE YYHSVDPIYF KNSEWEIEGS MNNIHKARVR ATVKPIKTMD LASSILTKLE
ALAGANGKRA IQQELARRAE EEKQRKRKAL DEMLK
