title: The role of the preserved sequences of Dam methylase.
abstract: We have undertaken a site directed mutational analysis of two of the preserved regions in the amino acid sequence of Dam methylase in order to characterize their role. Mutations in region IV (sequence DPPY) abolish catalytic activity and greatly affect AdoMet crosslinking. Mutants in region III display a lowered specific activity with an unchanged AdoMet crosslinking capacity. We have also made a series of deletions both at the N and C terminal parts of the protein, which have been found to provide inactive enzyme. We discuss the significance of these results for the understanding of the functional properties of the enzyme.
authors.affiliation: Département de Biologie Cellulaire et Moléculaire, Centre d'Etudes de Saclay, Gif-sur-Yvette, France.
authors.forename: J B
authors.initials: JB
authors.lastname: Guyot
authors.forename: J
authors.initials: J
authors.lastname: Grassi
authors.forename: U
authors.initials: U
authors.lastname: Hahn
authors.forename: W
authors.initials: W
authors.lastname: Guschlbauer
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000737:chemistry / Q000235:genetics; D000818:Animals; D001483:Base Sequence; D002417:Cattle; D017124:Conserved Sequence; D004247:DNA; D007124:Immunoenzyme Techniques; D008780:Methyltransferases / Q000737:chemistry* / Q000235:genetics; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D016133:Polymerase Chain Reaction; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific)
chemical_list: D000596:Amino Acids; D004247:DNA; D008780:Methyltransferases; C058693:Dam methyltransferase; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific)