Rho and NusG suppress pervasive antisense transcription in Escherichia coli
- Jason M. Peters1,2,5,
- Rachel A. Mooney1,
- Jeffrey A. Grass1,3,
- Erik D. Jessen1,2,
- Frances Tran1,3,6 and
- Robert Landick1,3,4,7
- 1Department of Biochemistry,
- 2Department of Genetics,
- 3Great Lakes Bioenergy Research Center,
- 4Department of Bacteriology, University of Wisconsin, Madison, Wisconsin 53706, USA
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.
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Footnotes
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↵7 Corresponding author
E-mail landick{at}bact.wisc.edu
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Supplemental material is available for this article.
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Article is online at http://www.genesdev.org/cgi/doi/10.1101/gad.196741.112.
- Received July 2, 2012.
- Accepted October 15, 2012.
- Copyright © 2012 by Cold Spring Harbor Laboratory Press