GcpE is involved in the 2-C-methyl-D-erythritol 4-phosphate pathway of isoprenoid biosynthesis in Escherichia coli

In a variety of organisms, including plants and several eubacteria, isopren oids are synthesized by the mevalonate-independent 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway. Although different enzymes of this pathway have been described, the terminal biosynthetic steps of the MEP pathway have not been fully elucidated. In this work, we demonstrate that the gcpE gene of Escherichia coli is involved in this pathway. E. coli cells were geneticall y engineered to utilize exogenously provided mevalonate for isoprenoid bios ynthesis by the mevalonate pathway. These cells were then deleted for the e ssential gcpE gene and were viable only if the medium was supplemented with mevalonate or the cells were complemented with an episomal copy of gcpE.