The successful replication of genetic material is vital for cell division and bacterial replication. Research that furthers the understanding of DNA replication will aid in the development of new treatments for cancer, as well as for bacterial and viral infections. Currently, the Gram negative bacterium Escherichia coli (E. coli) has served as a model system for DNA replication. E. coli shares some homology with the Gram positive bacteria, but the two systems are not identical. The goal of the research proposed here is to investigate DNA replication in the Gram positive Bacillus subtilis. This will be the first detailed characterization of a Gram positive primase. The activity of the primase will be characterized with respect to the rate and size of primers synthesized in the presence of the primosomal proteins by monitoring primer synthesis using gel electrophoresis. Also, the interaction of the DNA primase with the replicative helicase will be monitored by BIAcore. Additionally, a reconstituted replication restart pathway substrate will be used to determine if primase activity is altered by the replicative DNA polymerases. Fluorescence resonance energy transfer will monitor whether the primase remains associated with the replication fork continuously. [unreadable] [unreadable]