Mutations in the essential Escherichia coli gene, yqgF, and their effects on transcription

• Published in: Journal of molecular microbiology and biotechnology Vol. 22; no. 1; pp. 17 - 23
• Main Authors: Iwamoto, Akira, Osawa, Atsushi, Kawai, Makiko, Honda, Hirofumi, Yoshida, Saori, Furuya, Nobuhisa, Kato, Jun-Ichi
• Format: Journal Article
• Language: English
• Published: Switzerland S. Karger AG 01.01.2012
• Subjects: Endodeoxyribonucleases - genetics; Endodeoxyribonucleases - metabolism; Escherichia coli; Escherichia coli - genetics; Escherichia coli - metabolism; Escherichia coli Proteins - genetics; Escherichia coli Proteins - metabolism; Genes, Essential; Mutant Proteins - genetics; Mutant Proteins - metabolism; Mutation; Rho Factor - metabolism; Terminator Regions, Genetic; Transcription, Genetic
• ISSN: 1464-1801; 1660-2412
• DOI: 10.1159/000336517

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.