The nut site of bacteriophage lambda is made of RNA and is bound by transcription antitermination factors on the surface of RNA polymerase.
The boxA and boxB components of the lambda nut site are important for transcriptional antitermination by the phage N protein. We show here that boxA and boxB RNA in N-modified transcription complexes are inaccessible to ribonucleases and have altered sensitivity to dimethylsulfate. N and NusA suffice to weakly protect boxB, independently of boxA and other factors. However, efficient protection of the entire nut site from ribonucleases requires boxA and boxB, N, NusA, NusB, S10, and NusG. Mutations in RNA polymerase, which inhibit antitermination by N in vivo, disallow protection of the nut site during transcription in vitro; therefore, the surface of RNA polymerase must coordinate the formation of complexes containing the antitermination factors and nut site RNA.
Nodwell
J R
JR
Banting and Best Department of Medical Research, University of Toronto, Canada.
Greenblatt
J
J
D010582:Bacteriophage lambda / Q000235:genetics*; D001483:Base Sequence; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics; D005814:Genes, Viral / Q000235:genetics; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D009690:Nucleic Acid Conformation; D012367:RNA, Viral / Q000235:genetics* / Q000378:metabolism; D013463:Sulfuric Acid Esters / Q000494:pharmacology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects / Q000502:physiology*; D054334:Viral Regulatory and Accessory Proteins / Q000235:genetics / Q000378:metabolism*
C059417:N protein, Bacteriophage lambda; D012367:RNA, Viral; D013463:Sulfuric Acid Esters; D014157:Transcription Factors; D054334:Viral Regulatory and Accessory Proteins; D012321:DNA-Directed RNA Polymerases; C007482:dimethyl sulfate