title: Properties of small rRNA methyltransferase RsmD: mutational and kinetic study.
abstract: Ribosomal RNA modification is accomplished by a variety of enzymes acting on all stages of ribosome assembly. Among rRNA methyltransferases of Escherichia coli, RsmD deserves special attention. Despite its minimalistic domain architecture, it is able to recognize a single target nucleotide G966 of the 16S rRNA. RsmD acts late in the assembly process and is able to modify a completely assembled 30S subunit. Here, we show that it possesses superior binding properties toward the unmodified 30S subunit but is unable to bind a 30S subunit modified at G966. RsmD is unusual in its ability to withstand multiple amino acid substitutions of the active site. Such efficiency of RsmD may be useful to complete the modification of a 30S subunit ahead of the 30S subunit's involvement in translation.
authors.affiliation: Lomonosov Moscow State University, Department of Chemistry and A.N. Belozersky Institute of Physico-Chemical Biology, Moscow 119992, Russia.
authors.forename: Olga V
authors.initials: OV
authors.lastname: Sergeeva
authors.forename: Irina V
authors.initials: IV
authors.lastname: Prokhorova
authors.forename: Yerdos
authors.initials: Y
authors.lastname: Ordabaev
authors.forename: Philipp O
authors.initials: PO
authors.lastname: Tsvetkov
authors.forename: Petr V
authors.initials: PV
authors.lastname: Sergiev
authors.forename: Alexey A
authors.initials: AA
authors.lastname: Bogdanov
authors.forename: Alexander A
authors.initials: AA
authors.lastname: Makarov
authors.forename: Olga A
authors.initials: OA
authors.lastname: Dontsova
mesh_terms: D019943:Amino Acid Substitution; D004926:Escherichia coli / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism / Q000493:pharmacokinetics; D008780:Methyltransferases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism / Q000493:pharmacokinetics; D012336:RNA, Ribosomal, 16S / Q000737:chemistry / Q000378:metabolism
chemical_list: D029968:Escherichia coli Proteins; D012336:RNA, Ribosomal, 16S; D008780:Methyltransferases; C518826:RsmD protein, E coli