Dr. Ray's research is concerned with the replication mechanisms of the unusual form of mitochondrial DNA (kinetoplast DNA or kDNA) in kinetoplastid protozoa. kDNA consists of a network of topologically interlocked minicircles and maxicircles present in a single highly condensed DNA-protein disc at the base of the flagellum. He has identified and purified kinetoplast-specific replication proteins and has localized these proteins to specific sites relative to the kDNA disc. Some replication proteins are present at the faces of the disc and others are located at antipodal sites flanking the disc. Several H1 histone-like proteins are present throughout the disc. A mitochondrial DNA primase PRI1 appears to be involved specifically in maxicircle replication and a second mitochondrial DNA primase PRI2 is required for minicircle replication. Current studies seek to determine the enzymatic mechanisms involved in initiating minicircle and maxicircle replication at their respective origins and the possible roles of the mitochondrial DNA primases in initiating replication.