Markerless Escherichia coli rrn Deletion Strains for Genetic Determination of Ribosomal Binding Sites.
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.
['Quan|Selwyn|S|', 'Skovgaard|Ole|O|http://orcid.org/0000-0002-4860-1847', 'McLaughlin|Robert E|RE|', 'Buurman|Ed T|ET|', 'Squires|Catherine L|CL|']
D000900:Anti-Bacterial Agents D001665:Binding Sites D024881:Drug Resistance, Bacterial D004926:Escherichia coli D009876:Operon D012335:RNA, Ribosomal D012343:RNA, Transfer D012270:Ribosomes D017384:Sequence Deletion
ribosome duplication genomic instability rrl rrs