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The mevalonate-independent biosynthetic pathway to isopentenyl diphosphate and dimethylallyl diphosphate, the universal precursors to the isoprenoids, operates in eubacteria, including Escherichia coli, in algae, and in the plastids of higher plants. A search of the Sanger Centre Streptomyces coelicolor genome database revealed open reading frames with ca. 40-50% identity at the deduced amino acid level to the first three E. coli enzymes of this pathway, corresponding to deoxyxylulose phosphate synthase, deoxyxylulose phosphate reductoisomerase and 2-C-methyl erythritol 4-phosphate cytidyltransferase. The coelicolor genes have been cloned and expressed in E. coli, and the recombinant proteins characterized physically and kinetically. The presence of the corresponding enzyme activities in Extracts of S. coelicolor CH999 further supports the operation of the mevalonate-independent pathway in this organism. Copyright

2-C-Methyl,D-erythritol 4-phosphate is transformed to 4-(cytidine 5'- diphospho)-2-C-methyl-D-erythritol in the presence of cytidine 5'- triphosphate by a novel Escherichia coli enzyme, 2-C-methyl-D-erythritol 4- phosphate cytidylyltransferase, involved in the nonmevalonate pathway. (C) 2000 Elsevier Science Ltd.