The present invention provides the structure of the enzyme 4-diphosphocytidyl-2-C-methylerythritol (CDP-ME) synthase, a member of the cytidyltransferase family of enzymes from Escherichia coli. CDP-ME is a critical intermediate in the mevalonate-independent pathway for isoprenoid biosynthesis in a number of prokaryotic organisms, in algae, in the plastids of plants, and in the malaria parasite. Since vertebrates synthesize isoprenoid precursors using a mevalonate pathway, CDP-ME synthase and other enzymes of the mevalonate-independent pathway for isoprenoid production represent attractive targets for the structure-based design of selective antibacterial, herbicidal, and antimalarial drugs. Accordingly, the present invention provides methods for screening for compounds that inhibit enzymes of the mevalonate-independent pathway and pharmaceutical compositions and antibacterial formulations thereof. Further provided are methods of inhibiting the enzymes of the pathway and bacterial terpenoid synthesis and methods for treating a subject suffering from a bacterial infection.