title: Mutations in the essential Escherichia coli gene, yqgF, and their effects on transcription.
abstract: The Escherichia coli yqgF gene is highly conserved across a broad spectrum of bacterial genomes. The gene was first identified as being essential for cell growth during screening for targets for broad-spectrum antibiotics. YqgF is structurally similar to RuvC, a Holliday junction resolvase, but its function has not been established. This study describes the isolation of a temperature-sensitive yqgF mutant, the growth of which was inhibited by rho or nusA multicopy plasmids, indicating that YqgF is involved in transcription. Rho is a global transcription termination factor that acts at Rho-dependent terminator sites, which exist not only at the ends of genes but also within genes. The transcription of genes possessing intragenic, or upstream, Rho-dependent terminators was reduced in temperature-sensitive yqgF mutants. This transcription inhibition was sensitive to the Rho inhibitor, bicyclomycin. In addition, the transcription of mutant tnaA genes defective for upstream Rho-dependent termination was not significantly affected by the yqgF mutation. Taken together, these results suggest that YqgF is involved in anti-termination at Rho-dependent terminators in vivo.
authors.affiliation: Department of Biology, Graduate School of Science, Tokyo Metropolitan University, Hachioji, Tokyo, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Iwamoto
authors.forename: Atsushi
authors.initials: A
authors.lastname: Osawa
authors.forename: Makiko
authors.initials: M
authors.lastname: Kawai
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Honda
authors.forename: Saori
authors.initials: S
authors.lastname: Yoshida
authors.forename: Nobuhisa
authors.initials: N
authors.lastname: Furuya
authors.forename: Jun-Ichi
authors.initials: J
authors.lastname: Kato
mesh_terms: D004706:Endodeoxyribonucleases / Q000235:genetics* / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism*; D020043:Genes, Essential; D050505:Mutant Proteins / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D012234:Rho Factor / Q000378:metabolism; D013728:Terminator Regions, Genetic; D014158:Transcription, Genetic
chemical_list: D029968:Escherichia coli Proteins; D050505:Mutant Proteins; D012234:Rho Factor; D004706:Endodeoxyribonucleases; C470945:YqgF protein, E coli