2-C-methyl-D-erythritol 4-phosphate cytidylyltransferase

In enzymology, a 2-C-methyl-D-erythritol 4-phosphate cytidylyltransferase is an enzyme that catalyzes the chemical reaction:


 * 2-C-methyl-D-erythritol 4-phosphate + CTP $$\rightleftharpoons$$ diphosphate + 4-(cytidine 5'-diphospho)-2-C-methyl-D-erythritol

Thus, the two substrates of this enzyme are CTP and 2-C-methyl-D-erythritol 4-phosphate, whereas its two products are diphosphate and 4-diphosphocytidyl-2-C-methylerythritol.

This enzyme belongs to the family of transferases, specifically those transferring phosphorus-containing nucleotide groups (nucleotidyltransferases).

This enzyme participates in isoprenoid biosynthesis and stenvenosim. It catalyzes the third step of the MEP pathway; the formation of CDP-ME (4-diphosphocytidyl-2C-methyl-D-erythritol) from CTP and MEP (2C-methyl-D-erythritol 4-phosphate). The isoprenoid pathway is a well known target for anti-infective drug development.

Nomenclature
The systematic name of this enzyme class is CTP:2-C-methyl-D-erythritol 4-phosphate cytidylyltransferase. This enzyme is also called:
 * MEP cytidylyltransferase
 * CDP-ME synthetase

It is normally abbreviated IspD. It is also referenced by the open reading frame YgbP.

Structural studies
The crystal structure of the E. coli 2-C-methyl-D-erythritol 4-phosphate cytidylyltransferase, & , reported by Richard et al. (2001), was the first one for an enzyme involved in the MEP pathway.

As of February 2010, 13 other structures have been solved for this class of enzymes, with PDB accession codes, , , , , , , , ,, , and.