title: A high-affinity interaction between NusA and the rrn nut site in Mycobacterium tuberculosis.
abstract: The bacterial NusA protein enhances transcriptional pausing and termination and is known to play an essential role in antitermination. Antitermination is signaled by a nut-like cis-acting RNA sequence comprising boxB, boxA, and boxC. In the present study, we demonstrate a direct, specific high-affinity interaction between the rrn leader nut-like sites and the NusA proteins of Mycobacterium tuberculosis and Escherichia coli. This NusA-RNA interaction relies on the conserved region downstream of boxA, the boxC region, thus demonstrating a key function of this element. We have established an in vivo assay for antitermination in mycobacteria and use this to show that the M. tuberculosis rrn nut-like site enhances transcriptional read-through of untranslated RNA consistent with an antitermination signal within this site. Finally, we present evidence that this NusA-RNA interaction affects transcriptional events further downstream.
authors.affiliation: Division of Mycobacterial Research, National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, United Kingdom. karnvig@nimr.mrc.ac.uk
authors.forename: Kristine B
authors.initials: KB
authors.lastname: Arnvig
authors.forename: S
authors.initials: S
authors.lastname: Pennell
authors.forename: B
authors.initials: B
authors.lastname: Gopal
authors.forename: M J
authors.initials: MJ
authors.lastname: Colston
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial; D008969:Molecular Sequence Data; D009169:Mycobacterium tuberculosis / Q000235:genetics / Q000378:metabolism*; D009690:Nucleic Acid Conformation; D010445:Peptide Elongation Factors / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D012329:RNA, Bacterial / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D013728:Terminator Regions, Genetic; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D035602:Transcriptional Elongation Factors
chemical_list: D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D010445:Peptide Elongation Factors; D012329:RNA, Bacterial; D011994:Recombinant Proteins; D014157:Transcription Factors; D035602:Transcriptional Elongation Factors; C068727:nusA protein, E coli