Roth 9408501 This Americas Program award will fund a collaborative research project between Dr. Monica Roth, Robert Wood Johnson Medical School, New Jersey, and Dr. Oscar Leon, Universidad Austral de Chile. They propose to use chemical cross-linking methods to study the interaction between retroviral RNase H and tRNA to determine which regions of the protein are at or near specific sites of the RNA-DNA hybrid substrate. This approach will also help to pinpoint amino acid sides chains that may be important for its function. For this purpose, RNA-DNA hybrid substrates of RNase H will be synthesized and modified at specific sites by the introduction of reactive groups. The studies are of mutual benefits for both laboratories involved and require a combination of the complementary skills of both researchers. Ongoing studies by Dr. Roth apply biochemical approaches to understand the mechanism of tRNA release by the RNase H activity and reverses transcriptase, while Dr. Leon's expertise is in chemical cross-linking of proteins and tRNA. The results of the studies are expected to contribute to the field of protein- nucleic acid recognition. Current procedures to be adapted for the specific application to RNA/DNA hybrids may be applicable to other similar systems. ***
