The research planned is to analyze specific representative enzymes in the daunomycin biosynthetic pathway to determine their substrate specificity, kinetics, and regulation as part of an assessment of possible differential regulation of the first one-half of the pathway in relation to the second one-half; such differential regulation may account for the failure of biosynthetic intermediates to be converted to the end-product antibiotic and, instead, to accumulate in cells. Molecular biological and genetic approaches will be employed to determine transcriptional and translational regulation of each enzyme in the pathway that has been purified, kinetics, etc., determined, so as to enlarge our understanding of the physiological and molecular genetic aspects of the regulation of the synthesis of this antibiotic, a product of secondary metabolite syntheses. Antibiotic synthesis and excretion is a characteristic of many bacteria and fungi and is a product of their "secondary metabolism"; the regulation of this type of metabolism is even less well understood than is central metabolism, and this project is directed at elucidating regulatory aspects of the secondary metabolism of a bacterium producing the antibiotic, daunomycin; this antibiotic's precursors accumulate in the producing cells rather than being converted entirely into the antibiotic; understanding what is responsible for this inefficiency may permit developments to improve the conversion and increase effectiveness of antibiotic production.
