This project involves a collaborative effort of two laboratories that are studying the mechanism by which genetic elements (transposons) move from one location on the chromosome to another in bacteria. Dr. Goryshin in Dr. S. Lanzov's laboratory in St. Petersburg is studying the excision process while Dr. Reznikoff is studying the movement process. The transposon Tn5 is a composite bacterial transposable element which consists of two nearly identical IS50 sequences bracketing 3 antibiotic resistance determinants. Tn5 and IS50 insertions have been found to be removed by a process called precise excision in which the structure of the interrupted gene is restored to its previous state. There exists evidence which suggests a relationship between this excision process and the transposition process; in particular IS50 excised. %%% Analyzing these relationships may provide us with fundamental knowledge regarding the role of protein DNA complexes in stimulating recombination and may help elucidate the mechanisms.
