title: The amoebapore superfamily.
abstract: Amoebapores, synthesized by human protozoan parasites, form ion channels in target cells and artificial lipid membranes. The major pathogenic effect of these proteins is due to their cytolytic capability which results in target cell death. They comprise a coherent family and are homologous to other proteins and protein domains found in eight families. These families include in addition to the amoebapores (1) the saposins, (2) the NK-lysins and granulysins, (3) the pulmonary surfactant proteins B, (4) the acid sphingomyelinases, (5) acyloxyacyl hydrolases and (6) the aspartic proteases. These amoebapore homologues have many properties in common including membrane binding and stability. We note for the first time that a new protein, countin, from the cellular slime mold, Dictyostelium discoideum, comprises the eighth family within this superfamily. All currently sequenced members of these eight families are identified, and the structural, functional and phylogenetic properties of these proteins are discussed.
authors.affiliation: Department of Biology, University of California at San Diego, 92093-0116, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Zhai
authors.forename: M H
authors.initials: MH
authors.lastname: Saier
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002265:Carboxylic Ester Hydrolases / Q000737:chemistry / Q000145:classification; D017124:Conserved Sequence; D003603:Cytotoxins / Q000737:chemistry / Q000235:genetics*; D004220:Disulfides / Q000737:chemistry; D004748:Entamoeba histolytica; D019143:Evolution, Molecular; D006023:Glycoproteins / Q000737:chemistry / Q000145:classification; D006801:Humans; D007473:Ion Channels; D008565:Membrane Proteins / Q000737:chemistry / Q000145:classification / Q000235:genetics*; D008969:Molecular Sequence Data; D010944:Plants; D011510:Proteolipids / Q000737:chemistry / Q000145:classification; D015800:Protozoan Proteins / Q000737:chemistry / Q000145:classification / Q000235:genetics*; D011663:Pulmonary Surfactants / Q000737:chemistry / Q000145:classification; D049231:Saposins; D016415:Sequence Alignment; D013108:Sphingomyelin Phosphodiesterase / Q000737:chemistry / Q000145:classification
chemical_list: D003603:Cytotoxins; D004220:Disulfides; D006023:Glycoproteins; D007473:Ion Channels; D008565:Membrane Proteins; C093238:NK-lysin; D011510:Proteolipids; D015800:Protozoan Proteins; D011663:Pulmonary Surfactants; D049231:Saposins; C041670:amoebapore proteins, protozoan; C120918:countin protein, Dictyostelium discoideum; D002265:Carboxylic Ester Hydrolases; C048964:acyloxyacyl hydrolase; C112980:acid sphingomyelinase-1; D013108:Sphingomyelin Phosphodiesterase