title: Translation repression by an RNA polymerase elongation complex.
abstract: Bacteriophage lambda N and bacterial Nus proteins together with a unique site NUT in the leader of the early viral N gene transcript bind RNA polymerase (RNAP) and form a highly processive antitermination complex; N bound at NUT also represses N translation. In this study, we investigate whether N and NUT cause N translation repression as part of the antitermination complex by testing conditions that inhibit the formation of the N-modified transcription complex for their effect on N-mediated translation repression. We show that nus and nut mutations that in combination destabilize multiple interactions in the antitermination complex prevent N-mediated translation repression. Likewise, transcription of the nut-N region by T7 RNAP, which does not lead to the assembly of an effective antitermination complex when N is supplied, eliminates translation repression. We also demonstrate that a unique mutant beta subunit of RNAP reduces N-mediated translation repression, and that overexpression of transcription factor NusA suppresses this defect. We conclude that the N-modified RNAP transcription complex is necessary to repress N translation.
authors.affiliation: Molecular Control and Genetics Section, Gene Regulation and Chromosome Biology, National Cancer Institute-Frederick, Frederick, MD 21702-1201, USA.
authors.forename: Helen R
authors.initials: HR
authors.lastname: Wilson
authors.forename: Jian-Guang
authors.initials: JG
authors.lastname: Zhou
authors.forename: Daiguan
authors.initials: D
authors.lastname: Yu
authors.forename: Donald L
authors.initials: DL
authors.lastname: Court
mesh_terms: D001483:Base Sequence; D012321:DNA-Directed RNA Polymerases / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics; D010443:Peptide Chain Termination, Translational / Q000235:genetics; D010957:Plasmids / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D014176:Protein Biosynthesis / Q000235:genetics*; D013489:Suppression, Genetic; D014158:Transcription, Genetic / Q000235:genetics
chemical_list: D012321:DNA-Directed RNA Polymerases