Genetic characterization of a bacterial locus involved in the activity of the N function of phage λ

Friedman, David I.; Baron, L. S.

doi:10.1016/0042-6822(74)90149-4

Cited by 136 publications

(79 citation statements)

References 14 publications

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“…The nusA1 and nusA11 substitution mutations, both of which affect the S1 domain of the protein, confer transcriptional polarity relief, but they are associated with additional phenotypes such as resistance (nusA1) and temperature sensitivity (nusA11) (23,39,53). Our findings also support those of Cardinale et al (9), who showed that a nusA insertion-deletion mutation, in the reduced-genome E. coli strain MDS42, renders transcription termination defective in the strain.…”

Section: Discussionsupporting

confidence: 81%

Compromised Factor-Dependent Transcription Termination in a nusA Mutant of Escherichia coli: Spectrum of Termination Efficiencies Generated by Perturbations of Rho, NusG, NusA, and H-NS Family Proteins

Saxena

Gowrishankar

2011

J Bacteriol

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The proteins NusA and NusG, which are essential for the viability of wild-type Escherichia coli, participate in various postinitiation steps of transcription including elongation, antitermination, and termination. NusG is required, along with the essential Rho protein, for factor-dependent transcription termination (also referred to as polarity), but the role of NusA is less clear, with conflicting reports that it both promotes and inhibits the process. In this study, we found that a recessive missense nusA mutant [nusA(R258C)] exhibits a transcription termination-defective (that is, polarity-relieved) phenotype, much like missense mutants in rho or nusG, but is unaffected for either the rate of transcription elongation or antitermination in phage. Various combinations of the rho, nusG, and nusA mutations were synthetically lethal, and the lethality was suppressed by expression of the N-terminal half of nucleoid protein H-NS. Our results suggest that NusA function is indeed needed for factor-dependent transcription termination and that an entire spectrum of termination efficiencies can be generated by perturbations of the Rho, NusG, NusA, and H-NS family of proteins, with the corresponding phenotypes extending from polarity through polarity relief to lethality.

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Section: Discussionsupporting

confidence: 81%

Compromised Factor-Dependent Transcription Termination in a nusA Mutant of Escherichia coli: Spectrum of Termination Efficiencies Generated by Perturbations of Rho, NusG, NusA, and H-NS Family Proteins

Saxena

Gowrishankar

2011

J Bacteriol

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“…As the best-characterized Nus (N utilizing substance) factor, NusA was first identified as the host factor involved in phage λ N-protein mediated antitermination. 6 NusA also plays an essential role in the formation of the antitermination complex in host cell rRNA synthesis, which ensures the large ribosomal RNA operons (typically >5 kb) get transcribed completely and rapidly in order to cope with rRNA requirement at high-growth rates. 7 Conversely, NusA has been shown to stimulate regulatory pausing of RNAP, slowing the overall rate of transcription elongation.…”

mentioning

confidence: 99%

The interaction between RNA polymerase and the elongation factor NusA

Yang

Lewis²

2010

RNA Biology

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“…The effects of mutations in the S1 homology region of NusA between amino acids 136 and 240 suggest that this region is important for antitermination. The nusA1 (L183R) and nusA R199A mutations both cause temperature-sensitive growth because of an inability of N to function at high temperature (Friedman 1971;Friedman and Baron 1974;T. Mah, Y. Zhou, N. Yu, J. Mogridge, E. Olsen, J. Greenblatt, and D. Friedman, unpubl.).…”

mentioning

confidence: 99%

The α subunit of E. coli RNA polymerase activates RNA binding by NusA

Mah¹,

Kuznedelov²,

Mushegian³

et al. 2000

Genes Dev.

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The Escherichia coli NusA protein modulates pausing, termination, and antitermination by associating with the transcribing RNA polymerase core enzyme. NusA can be covalently cross-linked to nascent RNA within a transcription complex, but does not bind RNA on its own. We have found that deletion of the 79 carboxy-terminal amino acids of the 495-amino-acid NusA protein allows NusA to bind RNA in gel mobility shift assays. The carboxy-terminal domain (CTD) of the ␣ subunit of RNA polymerase, as well as the bacteriophage N gene antiterminator protein, bind to carboxy-terminal regions of NusA and enable full-length NusA to bind RNA. Binding of NusA to RNA in the presence of ␣ or N involves an amino-terminal S1 homology region that is otherwise inactive in full-length NusA. The interaction of the ␣-CTD with full-length NusA stimulates termination. N may prevent termination by inducing NusA to interact with N utilization (nut) site RNA rather than RNA near the 3 end of the nascent transcript. Sequence analysis showed that the ␣-CTD contains a modified helix-hairpin-helix motif (HhH), which is also conserved in the carboxy-terminal regions of some eubacterial NusA proteins. These HhH motifs may mediate protein-protein interactions in NusA and the ␣-CTD.

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Genetic characterization of a bacterial locus involved in the activity of the N function of phage λ

Cited by 136 publications

References 14 publications

Compromised Factor-Dependent Transcription Termination in a nusA Mutant of Escherichia coli: Spectrum of Termination Efficiencies Generated by Perturbations of Rho, NusG, NusA, and H-NS Family Proteins

Compromised Factor-Dependent Transcription Termination in a nusA Mutant of Escherichia coli: Spectrum of Termination Efficiencies Generated by Perturbations of Rho, NusG, NusA, and H-NS Family Proteins

The interaction between RNA polymerase and the elongation factor NusA

The α subunit of E. coli RNA polymerase activates RNA binding by NusA

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