title: Identification of the RsmG methyltransferase target as 16S rRNA nucleotide G527 and characterization of Bacillus subtilis rsmG mutants.
abstract: The methyltransferase RsmG methylates the N7 position of nucleotide G535 in 16S rRNA of Bacillus subtilis (corresponding to G527 in Escherichia coli). Disruption of rsmG resulted in low-level resistance to streptomycin. A growth competition assay revealed that there are no differences in fitness between the rsmG mutant and parent strains under the various culture conditions examined. B. subtilis rsmG mutants emerged spontaneously at a relatively high frequency, 10(-6). Importantly, in the rsmG mutant background, high-level-streptomycin-resistant rpsL (encoding ribosomal protein S12) mutants emerged at a frequency 200 times greater than that seen for the wild-type strain. This elevated frequency in the emergence of high-level streptomycin resistance was facilitated by a mutation pattern in rpsL more varied than that obtained by selection of the wild-type strain.
authors.affiliation: National Food Research Institute, 2-1-12 Kannondai, Tsukuba, Ibaraki, 305-8642, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Nishimura
authors.forename: Shanna K
authors.initials: SK
authors.lastname: Johansen
authors.forename: Takashi
authors.initials: T
authors.lastname: Inaoka
authors.forename: Takeshi
authors.initials: T
authors.lastname: Hosaka
authors.forename: Shinji
authors.initials: S
authors.lastname: Tokuyama
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Tahara
authors.forename: Susumu
authors.initials: S
authors.lastname: Okamoto
authors.forename: Fujio
authors.initials: F
authors.lastname: Kawamura
authors.forename: Stephen
authors.initials: S
authors.lastname: Douthwaite
authors.forename: Kozo
authors.initials: K
authors.lastname: Ochi
mesh_terms: D001412:Bacillus subtilis / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D029968:Escherichia coli Proteins; D008780:Methyltransferases / Q000235:genetics* / Q000378:metabolism; D009154:Mutation; D012335:RNA, Ribosomal; D012336:RNA, Ribosomal, 16S / Q000378:metabolism*; D000091243:Ribosomal Protein S9; D013307:Streptomycin / Q000494:pharmacology
chemical_list: D029968:Escherichia coli Proteins; D012335:RNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D000091243:Ribosomal Protein S9; C000717190:RpsI protein, E coli; D008780:Methyltransferases; D013307:Streptomycin