Our discovery of a novel enzyme in mycobacteria (coenzyme-F420-dependent glucose-6-P dehydrogenase), and our recent demonstration that M. smegmatis mutants lacking this enzyme grow poorly and have increased sensitivity to oxidative stress suggest that F420 is important for Mycobacterium fitness. F420 involvement in Mycobacterium metabolism was unexpected, since it is an electron-transfer coenzyme seldom found in Bacteria, but commonly found in Archaea. Mycobacteria cause several serious diseases, including tuberculosis, leprosy, and AIDS opportunistic infections. If F420 is important for virulence, we think that understanding F420 metabolism and biosynthesis will provide clues on how to develop new classes of drugs active against mycobacterial disease. We propose to determine the genetic basis for coenzyme F420 biosynthesis in Mycobacterium, and to define the importance of this coenzyme for growth, oxidative stress response, and virulence. This will be achieved by isolating M. smegmatis mutants that cannot make F420, cloning and sequencing the genes affected, using this information to create F420-minus Mycobacterium tuberculosis mutants, evaluating the vitro properties of all mutants, and deducing as much as possible concerning the role of each gene. The virulence of M. tuberculosis mutants will be examined in macrophage and animal models. The main hypotheses are that: F420 is important to mycobacteria as a redox coenzyme in growth, protective oxidative stress response, or other aspects of metabolism; F420 is important for M. tuberculosis virulence; the F420 biosynthesis genes will be largely consistent with the proposed biosynthesis pathway in methanogenic Archaea.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
1R01GM056177-01A1
Application #
2628364
Study Section
Microbial Physiology and Genetics Subcommittee 2 (MBC)
Project Start
1998-06-01
Project End
2001-05-31
Budget Start
1998-06-01
Budget End
1999-05-31
Support Year
1
Fiscal Year
1998
Total Cost
Indirect Cost
Name
University of Iowa
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
041294109
City
Iowa City
State
IA
Country
United States
Zip Code
52242