2-C-Methyl-D-erythritol-2,4-cyclopyrophosphate

2-C-Methyl-D-erythritol-2,4-cyclopyrophosphate (MEcPP) is an intermediate compound in the methylerythritol phosphate pathway (MEP pathway), which is responsible for the biosynthesis of isoprenoids in many bacteria, algae, and plants. This pathway is an alternative to the mevalonate pathway found in animals and some other organisms.

Structure and Properties

2D structure of 2-C-Methyl-D-erythritol-2,4-cyclopyrophosphate

2-C-Methyl-D-erythritol-2,4-cyclopyrophosphate is a cyclic diphosphate ester of 2-C-methyl-D-erythritol. The compound is characterized by its cyclopyrophosphate group, which is a cyclic diphosphate moiety. This structure is crucial for its role in the MEP pathway, where it acts as a substrate for subsequent enzymatic reactions.

Biosynthesis

MEcPP is synthesized from 4-diphosphocytidyl-2-C-methyl-D-erythritol (CDP-ME) through the action of the enzyme 4-diphosphocytidyl-2-C-methyl-D-erythritol kinase (IspE). This enzyme catalyzes the phosphorylation of CDP-ME to form MEcPP, which is then further processed in the MEP pathway.

Role in the MEP Pathway

3D ball-and-stick model of 2-C-Methyl-D-erythritol-2,4-cyclopyrophosphate

In the MEP pathway, MEcPP serves as a precursor to (E)-4-hydroxy-3-methylbut-2-enyl diphosphate (HMBPP), which is the immediate precursor to the universal isoprenoid precursors isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP). The conversion of MEcPP to HMBPP is catalyzed by the enzyme 2-C-methyl-D-erythritol 2,4-cyclodiphosphate synthase (IspG).

Biological Significance

The MEP pathway, and thus MEcPP, is essential for the production of isoprenoids, which are vital components of cellular processes. Isoprenoids are involved in the synthesis of chlorophyll, carotenoids, quinones, and other important biomolecules. The pathway is also a target for the development of antibiotics and herbicides, as it is present in many pathogens and plants but absent in humans.

Related Pages

• Methylerythritol phosphate pathway
• Isoprenoid
• Mevalonate pathway