In addition to RecA, we are studying several other E. coli proteins involved in recombinational DNA repair. These include the RecF, RecO, and RecR proteins, which function early in recombinational processes, and the RuvA and RuvB proteins which function late. The RuvA and B proteins form a complex that plays a key role in processing branched DNA recombination intermediates. All of these proteins currently present a variety of challenging mechanistic questions. Our newest enterprise is an effort to examine a novel DNA deletion event in the ciliate, T. thermophila.
Ciliates are single-celled eukaryotes with two nuclei.
The micronucleus is analogous to a germline nucleus and is normally silent. The macronucleus is the vegetative nucleus, producing mRNA to support cell functions. During mating, the existing macronuclei are destroyed and replaced with new ones derived from the micronuclei. We are currently working on two of these deletion events, addressing mechanistic issues in vivo and in vitro.