title: 6His-Eco29kI methyltransferase methylation site and kinetic mechanism characterization.
abstract: A new type II 6His-Eco29kI DNA methyltransferase was tested for methylation site (CC(Me)GCGG) and catalytic reaction optimal conditions. With high substrate concentrations, an inhibitory effect of DNA, but not AdoMet, on its activity was observed. Isotope partitioning and substrate preincubation assays showed that the enzyme-AdoMet complex is catalytically active. Considering effect of different concentrations of DNA and AdoMet on initial velocity, ping-pong mechanisms were ruled out. According to data obtained, the enzyme appears to work by preferred ordered bi-bi mechanism with AdoMet as leading substrate.
authors.affiliation: Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Prospekt Nauki 5, Pushchino, Moscow Region 142290, Russia. dvnikitin@rambler.ru
authors.forename: Dmitri
authors.initials: D
authors.lastname: Nikitin
authors.forename: Marina
authors.initials: M
authors.lastname: Mokrishcheva
authors.forename: Alexander
authors.initials: A
authors.lastname: Solonin
mesh_terms: D000241:Adenosine / Q000031:analogs & derivatives / Q000737:chemistry; D001665:Binding Sites; D002384:Catalysis; D019175:DNA Methylation; D015257:DNA-Cytosine Methylases / Q000737:chemistry*; D004926:Escherichia coli / Q000201:enzymology*; D029968:Escherichia coli Proteins / Q000737:chemistry*; D005001:Ethionine / Q000031:analogs & derivatives / Q000737:chemistry; D007700:Kinetics; D013379:Substrate Specificity
chemical_list: D029968:Escherichia coli Proteins; C012167:S-adenosylethionine; D015257:DNA-Cytosine Methylases; D000241:Adenosine; D005001:Ethionine