title: Mutational analysis of basic residues in the N-terminus of the rRNA:m6A methyltransferase ErmC'.
abstract: Erm methyltransferases mediate the resistance to the macrolide-lincosamide-streptogramin B antibiotics via dimethylation of a specific adenine residue in 23S rRNA. The role of positively charged N-terminal residues of the ErmC' methyltransferase in RNA binding and/or catalysis was determined. Mutational analysis of amino acids K4 and K7 was performed and the mutants were characterized in in vivo and in vitro experiments. The K4 and K7 residues were suggested not to be essential for the enzyme activity but to provide a considerable support for the catalytic step of the reaction, probably by maintaining the optimum conformation of the transition state through interactions with the phosphate backbone of RNA.
authors.affiliation: Department of Biochemistry and Molecular Biology, Faculty of Pharmacy and Biochemistry, Univesity of Zagreb, 10000 Zagreb, Croatia. gordana@pharma.hr
authors.forename: G
authors.initials: G
authors.lastname: Maravić
authors.forename: J M
authors.initials: JM
authors.lastname: Bujnicki
authors.forename: M
authors.initials: M
authors.lastname: Flögel
mesh_terms: D000595:Amino Acid Sequence; D024361:Amino Acids, Basic / Q000235:genetics; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001412:Bacillus subtilis / Q000201:enzymology* / Q000235:genetics*; D017124:Conserved Sequence; D004269:DNA, Bacterial / Q000235:genetics / Q000502:physiology; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D004917:Erythromycin / Q000494:pharmacology; D016368:Frameshift Mutation; D008780:Methyltransferases / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism / Q000502:physiology*; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009843:Oligoribonucleotides / Q000378:metabolism; D017433:Protein Structure, Secondary; D012329:RNA, Bacterial / Q000378:metabolism; D012338:RNA, Ribosomal, 23S / Q000378:metabolism; D012436:S-Adenosylmethionine / Q000378:metabolism; D016415:Sequence Alignment
chemical_list: D024361:Amino Acids, Basic; D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D009843:Oligoribonucleotides; D012329:RNA, Bacterial; D012338:RNA, Ribosomal, 23S; D004917:Erythromycin; D012436:S-Adenosylmethionine; D008780:Methyltransferases; C035181:rRNA (adenosine-O-2'-)methyltransferase