title: Rho and NusG suppress pervasive antisense transcription in Escherichia coli.
abstract: Despite the prevalence of antisense transcripts in bacterial transcriptomes, little is known about how their synthesis is controlled. We report that a major function of the Escherichia coli termination factor Rho and its cofactor, NusG, is suppression of ubiquitous antisense transcription genome-wide. Rho binds C-rich unstructured nascent RNA (high C/G ratio) prior to its ATP-dependent dissociation of transcription complexes. NusG is required for efficient termination at minority subsets (~20%) of both antisense and sense Rho-dependent terminators with lower C/G ratio sequences. In contrast, a widely studied nusA deletion proposed to compromise Rho-dependent termination had no effect on antisense or sense Rho-dependent terminators in vivo. Global colocalization of the histone-like nucleoid-structuring protein (H-NS) with Rho-dependent terminators and genetic interactions between hns and rho suggest that H-NS aids Rho in suppression of antisense transcription. The combined actions of Rho, NusG, and H-NS appear to be analogous to the Sen1-Nrd1-Nab3 and nucleosome systems that suppress antisense transcription in eukaryotes.
authors.affiliation: Department of Biochemistry, University of Wisconsin, Madison, WI 53706, USA.
authors.forename: Jason M
authors.initials: JM
authors.lastname: Peters
authors.forename: Rachel A
authors.initials: RA
authors.lastname: Mooney
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Grass
authors.forename: Erik D
authors.initials: ED
authors.lastname: Jessen
authors.forename: Frances
authors.initials: F
authors.lastname: Tran
authors.forename: Robert
authors.initials: R
authors.lastname: Landick
mesh_terms: D001483:Base Sequence; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial; D016680:Genome, Bacterial; D010445:Peptide Elongation Factors / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D029968:Escherichia coli Proteins; C070291:NusG protein, E coli; D010445:Peptide Elongation Factors; C534627:Rho protein, E coli; D014157:Transcription Factors