A central step of gene expression is the transcription of DNA into RNA. The DNA-dependent RNA polymerase (RNAP) is the enzyme that catalyzes the formation of phosphodiester bonds to polymerize the RNA chain in all cellular organisms. In addition to the core RNAP protein, prokaryotes also require the sigma subunit, which binds core RNAP to form the holoenzyme, to achieve specificity of promoter recognition and initiation. When the holoenzyme interacts with promoter DNA to form the closed complex, a series of isomerization steps occur to yield the transcription-competent open complex, where the doublestranded DNA is melted over a 14 base pair region of DNA that includes the start site at +1. Extensive biochemical work by others indicates that region 2 of sigma plays a key role in the formation of the open complex. To further understand how the transition from closed to open promoter complex occurs and to specifically define the protein interactions between region 2 of sigma and DNA that are key to this transition, this research proposal is aimed at obtaining a high resolution structure (better than 3.5 Angstrom resolution) of the RNAP holoenzyme/promoter DNA complex.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Postdoctoral Individual National Research Service Award (F32)
Project #
5F32GM072326-02
Application #
6916368
Study Section
Special Emphasis Panel (ZRG1-F04B (20))
Program Officer
Flicker, Paula F
Project Start
2004-07-01
Project End
2006-06-30
Budget Start
2005-07-01
Budget End
2006-06-30
Support Year
2
Fiscal Year
2005
Total Cost
$48,296
Indirect Cost
Name
Rockefeller University
Department
Physiology
Type
Other Domestic Higher Education
DUNS #
071037113
City
New York
State
NY
Country
United States
Zip Code
10065
Patikoglou, Georgia A; Westblade, Lars F; Campbell, Elizabeth A et al. (2007) Crystal structure of the Escherichia coli regulator of sigma70, Rsd, in complex with sigma70 domain 4. J Mol Biol 372:649-59
Kuznedelov, Konstantin; Lamour, Valerie; Patikoglou, Georgia et al. (2006) Recombinant Thermus aquaticus RNA polymerase for structural studies. J Mol Biol 359:110-21