Preliminary work establishes that three natural products-the polyketide-derived a-pyrone myxopyronin, the Dolyketide-derived a-pyrone corallopyronin, and the polyketide-derived macrocylic lactone ripostatin-inhibit bacterial RNA polymerase (RNAP) through interactions with the RNAP """"""""switch region,"""""""" a structural element that mediates conformational changes required for RNAP to bind and retain the DNA template in transcription. The compounds do not inhibit eukaryotic RNAP I, RNAP II, or RNAP III. The compounds potently inhibit Gram-positive and Gram-negative bacterial growth, exhibit no cross-resistance with the inhibitors of bacterial RNAP in current clinical use in therapy of bacterial infection (the rifamycin antibacterial agents, rifampicin, rifapentine, and rifabutin), and exhibit no cross-resistance with other inhibitors of bacterial RNAP under evaluation for future clinical use in therapy of bacterial infection. The proposed work will use x-ray crystallography, ensemble and single-molecule fluorescence resonance energy transfer, single-molecule nanomanipulation, molecular cloning, surrogate-host expression, structure-based screening, and de novo screening, to address four specific aims: ? ? Specific Aim 1: Determination of structures of complexes of RNAP with switch-region-target inhibitors Specific Aim 2: Determination of mechanisms of inhibition of RNAP by switch-region-target inhibitors Specific Aim 3: Cloning, characterization, and surrogate-host expression of biosynthetic gene clusters for switch-region-target inhibitors ? Specific Aim 4: Identification and characterization of novel switch-region-target inhibitors. ? ? The results will enable development of new broad-spectrum antibacterial agents that will be effective against bacterial strains resistant to currently used antibacterial agents. As such, the results will have direct relevance to public health and to development of countermeasures against bacterial strains that could be used in biowarfare or bioterrorism. In addition, the results will contribute to understanding RNAP structure and function and will provide tools for analysis of RNAP structure and function. ? ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
1R01AI072766-01
Application #
7187263
Study Section
Drug Discovery and Mechanisms of Antimicrobial Resistance Study Section (DDR)
Program Officer
Peters, Kent
Project Start
2007-01-01
Project End
2011-12-31
Budget Start
2007-01-01
Budget End
2007-12-31
Support Year
1
Fiscal Year
2007
Total Cost
$598,532
Indirect Cost
Name
Rutgers University
Department
Type
Organized Research Units
DUNS #
001912864
City
New Brunswick
State
NJ
Country
United States
Zip Code
08901
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