title: A multipronged strategy of an anti-terminator protein to overcome Rho-dependent transcription termination.
abstract: One of the important role of Rho-dependent transcription termination in bacteria is to prevent gene expressions from the bacteriophage DNA. The transcription anti-termination systems of the lambdoid phages have been designed to overcome this Rho action. The anti-terminator protein N has three interacting regions, which interact with the mRNA, with the NusA and with the RNA polymerase. Here, we show that N uses all these interaction modules to overcome the Rho action. N and Rho co-occupy their overlapping binding sites on the nascent RNA (the nutR/tR1 site), and this configuration slows down the rate of ATP hydrolysis and the rate of RNA release by Rho from the elongation complex. N-RNA polymerase interaction is not too important for this Rho inactivation process near/at the nutR site. This interaction becomes essential when the elongation complex moves away from the nutR site. From the unusual NusA-dependence property of a Rho mutant E134K, a suppressor of N, we deduced that the N-NusA complex in the anti-termination machinery reduces the efficiency of Rho by removing NusA from the termination pathway. We propose that NusA-remodelling is also one of the mechanisms used by N to overcome the termination signals.
authors.affiliation: Laboratory of Transcription, Center for DNA Fingerprinting and Diagnostics, Tuljaguda Complex, 4-1-714 Mozamjahi Road, Nampally, Hyderabad 500 001, India.
authors.forename: Ghazala
authors.initials: G
authors.lastname: Muteeb
authors.forename: Debashish
authors.initials: D
authors.lastname: Dey
authors.forename: Saurabh
authors.initials: S
authors.lastname: Mishra
authors.forename: Ranjan
authors.initials: R
authors.lastname: Sen
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000378:metabolism; D010445:Peptide Elongation Factors / Q000378:metabolism; D012329:RNA, Bacterial / Q000737:chemistry / Q000378:metabolism; D012234:Rho Factor / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D013489:Suppression, Genetic; D014157:Transcription Factors / Q000378:metabolism; D061806:Transcription Termination, Genetic; D035602:Transcriptional Elongation Factors; D014764:Viral Proteins / Q000378:metabolism; D054334:Viral Regulatory and Accessory Proteins / Q000378:metabolism*
chemical_list: D029968:Escherichia coli Proteins; C059417:N protein, Bacteriophage lambda; C070291:NusG protein, E coli; C119762:NutR protein, bacteriophage lambda; D010445:Peptide Elongation Factors; D012329:RNA, Bacterial; D012234:Rho Factor; D014157:Transcription Factors; D035602:Transcriptional Elongation Factors; D014764:Viral Proteins; D054334:Viral Regulatory and Accessory Proteins; C068727:nusA protein, E coli; D000255:Adenosine Triphosphate; D012321:DNA-Directed RNA Polymerases