9412816 Abstract The bacterium E. coli provides a good model system for the study of genetic recombination. The ease with which it is maintained and genetically manipulated has allowed the isolation and analysis of a large number of recombination deficient mutants and the subsequent identification and analysis of the genes and respective gene products. Many of the genes involved in homologous recombination are also required for some aspect of DNA repair. There are at least three distinct recombination pathways termed RecBCD, RecE, and RecF which differ from each other with respect to the gene product(s) required. Both the RecBCD and RecF pathways function in wild type cells, and both are believed to require the recA gene product. At least twelve additional recombination genes are involved in some aspect of RecF pathway recombination, yet very little is known about the interaction between the RecF pathway gene products and how they function together in recombination. All RecF pathway mediated recombination requires the recO and recR gene products. In addition, both gene products are essential for DNA repair following UV irradiation or mitomycin C exposure. Purified RecO protein shares some biochemical activities with RecA protein including D-loop formation, and RecO can substitute for RecA in vivo, suggesting that the two proteins are functionally similar. The goal of this research is to further investigate the function of RecO protein in vivo, and to identify and characterize the biochemical properties associated with RecO in vitro that are relevant to RecO function in recombination and DNA repair. *** One aspect of DNA metabolism that is not well characterized at the molecular level is general recombination. Recombination mechanisms are essential to generate genetic diversity, to maintain cell viability after DNA damage, and to accurately segregate chromosomes during meiosis. %%%
