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

In enzymology, a 2-C-methyl-D-erythritol 4-phosphate cytidylyltransferase (EC 2.7.7.60) is an enzyme that catalyzes the chemical reaction:

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

• 
  2-C-methylerythritol 4-phosphate
• 
  Cytidine triphosphate
• 
  4-diphosphocytidyl-2-C-methylerythritol (CDP-ME)

2-C-methyl-D-erythritol 4-phosphate cytidylyltransferase
Identifiers
EC no.	2.7.7.60
CAS no.	251990-59-7
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Gene Ontology	AmiGO / QuickGO
Search PMC articles PubMed articles NCBI proteins

IspD
2-C-methyl-D-erythritol 4-phosphate cytidylyltransferase (IspD) from Arabidopsis thaliana
Identifiers
Symbol	IspD
Pfam	PF01128
Pfam clan	CL0110
InterPro	IPR001228
PROSITE	PDOC00997
SCOP2	1inj / SCOPe / SUPFAM
Available protein structures: Pfam   structures / ECOD   PDB RCSB PDB; PDBe; PDBj PDBsum structure summary

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).^[1] The isoprenoid pathway is a well known target for anti-infective drug development.^[2][3]

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 1I52, 1INI & 1INJ, 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 1H3M, 1VGT, 1VGU, 1VGZ, 1VPA, 1VGW, 1W55, 1W57, 1W77,2PX7, 2VSI, 3F1C and 2VSH.