title: Widespread phylogenetic distribution of a protein methyltransferase that modifies L-isoaspartyl residues.
abstract: Protein L-isoaspartyl methyltransferase is implicated in the repair or degradation of age-damaged proteins that contain atypical, L-isoaspartyl residues. The enzyme has previously been demonstrated in a variety of vertebrates and in the bacterium S. typhimurium (O'Connor, C.M. and Clarke, S. (1985) Biochem. Biophys. Res. Commun. 132, 1144-1150). We report here that the enzyme is present in a mollusc (great slug), a crustacean (pill woodlouse), a fungus (mushroom), and a plant (wheat germ). Using mushroom as an example, we show that the enzyme activity may, in some instances, require a partial purification before its presence is clearly detectable. Our findings significantly extend the known phylogenetic distribution of this enzyme and suggest that it may play an indispensable role in protein metabolism.
authors.affiliation: School of Biological Sciences, University of California, Irvine 92717.
authors.forename: B A
authors.initials: BA
authors.lastname: Johnson
authors.forename: S Q
authors.initials: SQ
authors.lastname: Ngo
authors.forename: D W
authors.initials: DW
authors.lastname: Aswad
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001487:Basidiomycota / Q000201:enzymology; D001921:Brain / Q000201:enzymology; D002417:Cattle; D002852:Chromatography, Ion Exchange; D003445:Crustacea / Q000201:enzymology; D008969:Molecular Sequence Data; D008974:Mollusca / Q000201:enzymology; D010802:Phylogeny; D010944:Plants / Q000201:enzymology; D026601:Protein D-Aspartate-L-Isoaspartate Methyltransferase; D011496:Protein Methyltransferases / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D011506:Proteins; D011496:Protein Methyltransferases; D026601:Protein D-Aspartate-L-Isoaspartate Methyltransferase