title: Markerless Escherichia coli rrn Deletion Strains for Genetic Determination of Ribosomal Binding Sites.
abstract: Single-copy rrn strains facilitate genetic ribosomal studies in Escherichia coli. Consecutive markerless deletion of rrn operons resulted in slower growth upon inactivation of the fourth copy, which was reversed by supplying transfer RNA genes encoded in rrn operons in trans. Removal of the sixth, penultimate rrn copy led to a reduced growth rate due to limited rrn gene dosage. Whole-genome sequencing of variants of single-copy rrn strains revealed duplications of large stretches of genomic DNA. The combination of selective pressure, resulting from the decreased growth rate, and the six identical remaining scar sequences, facilitating homologous recombination events, presumably leads to elevated genomic instability.
authors.affiliation: Department of Biology, Stanford University, Stanford, California 094305.
authors.forename: Selwyn
authors.initials: S
authors.lastname: Quan
authors.affiliation: Department of Science, Systems and Models, Roskilde University, DK-4000 Roskilde, Denmark.
authors.forename: Ole
authors.identifier: http://orcid.org/0000-0002-4860-1847
authors.initials: O
authors.lastname: Skovgaard
authors.affiliation: Department of Biosciences, Infection Innovative Medicines Unit, AstraZeneca R&D Boston, Waltham, Massachusetts 02451.
authors.forename: Robert E
authors.initials: RE
authors.lastname: McLaughlin
authors.affiliation: Department of Biosciences, Infection Innovative Medicines Unit, AstraZeneca R&D Boston, Waltham, Massachusetts 02451 Ed.Buurman@pfizer.com.
authors.forename: Ed T
authors.initials: ET
authors.lastname: Buurman
authors.affiliation: Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts 02111.
authors.forename: Catherine L
authors.initials: CL
authors.lastname: Squires
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001665:Binding Sites; D024881:Drug Resistance, Bacterial; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism*; D009876:Operon; D012335:RNA, Ribosomal / Q000235:genetics; D012343:RNA, Transfer / Q000235:genetics; D012270:Ribosomes / Q000378:metabolism*; D017384:Sequence Deletion
chemical_list: D000900:Anti-Bacterial Agents; D012335:RNA, Ribosomal; D012343:RNA, Transfer
keywords: duplication; genomic instability; ribosome; rrl; rrs