Research in the Bell lab uses x-ray crystallography and other biochemical and biophysical tools to understand the mechanisms of proteins involved in DNA repair and other important biological processes. One area of interest is E. coli RecA protein, which promotes the central DNA strand-exchange step of DNA repair by homologous recombination. A second project involves the phage-based RecET and Redab recombination systems, which each consist of a ring-shaped exonuclease (RecE or Red) that binds to dsDNA ends and processively digests the 5’-ended strand into mononucleotides, and a single strand annealing protein (RecT or Reda), that loads onto the resulting 3’-overhang to promote the annealing of complementary strands. The proteins of these recombination systems are currently being exploited in exciting new methods for genetic engineering and nanopore DNA sequencing, and our research is aimed at providing a structural framework for understanding and re-engineering their functional properties. The structural work is complemented by a thorough structure- function analysis, which involves biochemical and biophysical assays utilizing fluorescence or gel-based methods.
