Translation repression by an RNA polymerase elongation complex.
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.
Wilson
Helen R
HR
Molecular Control and Genetics Section, Gene Regulation and Chromosome Biology, National Cancer Institute-Frederick, Frederick, MD 21702-1201, USA.
Zhou
Jian-Guang
JG
Yu
Daiguan
D
Court
Donald L
DL
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
D012321:DNA-Directed RNA Polymerases