Research Summary

Dr. Buck's research focuses on the regulation of genes involved in DNA repair. One gene, nfi, encodes the repair enzyme Endonuclease V, which cleaves DNA containing numerous types of lesions, including nitrosative deamination of nucleobases. The long-term goal is to determine how this gene is regulated within bacteria living within natural environments, rather than within closed or batch systems, in which bacteria are less exposed to exogenous substances from the environment. One hypothesis is that nfi is regulated as part of a regulon, a coordinately expressed group of genes or operons scattered throughout the chromosome. Recently reported work suggested that heavy metals might affect repair of DNA lesions as part of a network. Dr. Buck's lab uses E. coli isolated from the environment as a model organism to study control networks in other estuarine and marine bacteria. Preliminary data show that some heavy metals in the presence of nitrite inhibit growth, and future experiments will use RT-PCR, ribonuclease protection assays, and microarrays to determine which gene(s) may be involved. Dr. Buck also collaborates with Dr. Chopin and her students on the antibacterial properties of plant extracts indigenous to northern Mexico and with Dr. Mott on the study of bacteria found in aquatic environments, and the animal sources of those bacteria.