We will investigate two fundamental processes of genetic control in E. coli, which are models for genetic regulation in all cells. 1. The protein encoded by bacteriophage lambda gene Q invokes phage late gene expression by acting in a specific operon as a transcription antiterminator. Antitermination is an important mechanism of regulation in bacteria, and possibly in all cells and viruses. We will determine how lambda Q protein is engaged by RNA polymerase at a genome-specific site near the promoter, using chemical and nuclease protection methods to probe its interaction with DNA, and using mutations we will make that change this interaction in specific ways. We will determine how Q protein modifies the properties of RNA polymerase to allow it to pass transcription terminators, and how it changes the ability of RNA polymerase to pause at characteristic sites. We will investigate the role of the transcription factor NusA protein in antitermination. 2. In addition to catalyzing DNA strand exchange in genetic recombination, the E. coli RecA protein mediates induction of the SOS genes, which include DNA repair functions required for mutagenesis by most important carcinogens. Carcinogens are also inducers of SOS genes (and phage lambda), because they lead to activation of RecA protein to bind and destroy by proteolytic cleavage the LexA repressor of the SOS genes, as well as temperate phage repressors. To test the model that induction occurs when chromosome replication uncovers gaps in DNA at the sites of carcinogen-induced lesions, we will determine the relation between LexA cleavage and DNA replication. To test the universality of this regulation, we will study an analogue of RecA protein in the distantly related bacterium B. subtilis.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM021941-15
Application #
3270811
Study Section
Microbial Physiology and Genetics Subcommittee 2 (MBC)
Project Start
1978-02-01
Project End
1991-01-31
Budget Start
1989-02-01
Budget End
1990-01-31
Support Year
15
Fiscal Year
1989
Total Cost
Indirect Cost
Name
Cornell University
Department
Type
Schools of Arts and Sciences
DUNS #
City
Ithaca
State
NY
Country
United States
Zip Code
14850
Bird, Jeremy G; Strobel, Eric J; Roberts, Jeffrey W (2016) A universal transcription pause sequence is an element of initiation factor ?70-dependent pausing. Nucleic Acids Res 44:6732-40
Strobel, Eric J; Roberts, Jeffrey W (2015) Two transcription pause elements underlie a ?70-dependent pause cycle. Proc Natl Acad Sci U S A 112:E4374-80
Strobel, Eric J; Roberts, Jeffrey W (2014) Regulation of promoter-proximal transcription elongation: enhanced DNA scrunching drives ?Q antiterminator-dependent escape from a ?70-dependent pause. Nucleic Acids Res 42:5097-108
Liu, Xiaoqiu; Jiang, Huifeng; Gu, Zhenglong et al. (2013) High-resolution view of bacteriophage lambda gene expression by ribosome profiling. Proc Natl Acad Sci U S A 110:11928-33
Perdue, Sarah A; Roberts, Jeffrey W (2010) A backtrack-inducing sequence is an essential component of Escherichia coli ?(70)-dependent promoter-proximal pausing. Mol Microbiol 78:636-50
Hatoum, Asma; Roberts, Jeffrey (2008) Prevalence of RNA polymerase stalling at Escherichia coli promoters after open complex formation. Mol Microbiol 68:17-28
Roberts, Jeffrey W; Shankar, Smita; Filter, Joshua J (2008) RNA polymerase elongation factors. Annu Rev Microbiol 62:211-33
Davydova, Elena K; Santangelo, Thomas J; Rothman-Denes, Lucia B (2007) Bacteriophage N4 virion RNA polymerase interaction with its promoter DNA hairpin. Proc Natl Acad Sci U S A 104:7033-8
Park, Joo-Seop; Roberts, Jeffrey W (2006) Role of DNA bubble rewinding in enzymatic transcription termination. Proc Natl Acad Sci U S A 103:4870-5
Holmes, Shannon F; Santangelo, Thomas J; Cunningham, Candice K et al. (2006) Kinetic investigation of Escherichia coli RNA polymerase mutants that influence nucleotide discrimination and transcription fidelity. J Biol Chem 281:18677-83

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