Effect of Escherichia coli nusG function on lambda N-mediated transcription antitermination.
The Escherichia coli Nus factors act in conjunction with the bacteriophage lambda N protein to suppress transcription termination on the lambda chromosome. NusA binds both N and RNA polymerase and may also interact with other Nus factors. To search for additional components of the N antitermination system, we isolated host revertants that restored N activity in nusA1 mutants. One revertant, nusG4, was mapped to the rif region of the E. coli chromosome and shown to represent a point mutation near the 3' end of the nusG gene. The nusG4 mutation also suppressed nusE71 but not nusASal, nusB5, nusC60 (rpoB60), or nusD026 (rho026). However, nusG+ expressed from a multicopy plasmid suppressed nusD026 and related rho mutants for both lambda and phage T4 growth. These results suggest that NusG may act as a component of the N antitermination complex. In addition, the data imply a role for NusG in Rho-dependent termination.
Sullivan
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SL
Institute of Cancer Research, Columbia University College of Physicians and Surgeons, New York, New York 10032.
Ward
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Gottesman
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ME
D001426:Bacterial Proteins / Q000235:genetics*; D010582:Bacteriophage lambda / Q000235:genetics*; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D004279:DNA, Viral / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins; D005686:Galactokinase / Q000235:genetics / Q000378:metabolism; D016153:Genes, Suppressor / Q000235:genetics; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D010445:Peptide Elongation Factors / Q000235:genetics*; D012234:Rho Factor / Q000235:genetics; D014157:Transcription Factors; D014158:Transcription, Genetic / Q000235:genetics*; D054334:Viral Regulatory and Accessory Proteins / Q000235:genetics*; D001616:beta-Galactosidase / Q000235:genetics / Q000378:metabolism
D001426:Bacterial Proteins; D004279:DNA, Viral; D029968:Escherichia coli Proteins; C059417:N protein, Bacteriophage lambda; C070291:NusG protein, E coli; D010445:Peptide Elongation Factors; D012234:Rho Factor; D014157:Transcription Factors; D054334:Viral Regulatory and Accessory Proteins; D005686:Galactokinase; D001616:beta-Galactosidase