title: Studies on the function of conserved sequence motifs in the T4 Dam-[N6-adenine] and EcoRII [C5-cytosine] DNA methyltransferases.
abstract: We used site-directed oligodeoxyribonucleotide-mediated mutagenesis and kinetic studies with purified wild-type (wt) and mutant proteins to evaluate the role of the conserved sequence motifs in two prokaryotic DNA MTases. We suggest that: (i) the main role of Pro in the M.EcoRII PC-motif is to restrict the conformational freedom of Cys and orient it in a manner essential for catalysis; (ii) in both M.EcoRII and T4 Dam the FXGXG-motif positions AdoMet with respect to the catalytic site; (iii) the DPPY-motif in T4 Dam (region IV) is important for AdoMet-binding and may be part of the binding site; and (iv) the RXNXKXXFXXPFK-motif in T4 Dam (region III) is part of the DNA binding/recognition domain.
authors.affiliation: Department of Biology, University of Rochester, NY 14627, USA.
authors.forename: V G
authors.initials: VG
authors.lastname: Kossykh
authors.forename: S L
authors.initials: SL
authors.lastname: Schlagman
authors.forename: S
authors.initials: S
authors.lastname: Hattman
mesh_terms: D000595:Amino Acid Sequence; D017122:Bacteriophage T4 / Q000201:enzymology*; D001665:Binding Sites; D017124:Conserved Sequence; D004252:DNA Mutational Analysis; D015257:DNA-Cytosine Methylases / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism*; D007700:Kinetics; D008780:Methyltransferases / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism*; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific); D014764:Viral Proteins
chemical_list: D011994:Recombinant Proteins; D014764:Viral Proteins; C029528:DNA modification methylase EcoRII; D015257:DNA-Cytosine Methylases; D008780:Methyltransferases; C058693:Dam methyltransferase; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific); C499297:dam protein, Bacteriophage T4