InterPro domain: IPR036571

IspF is a MECDP (2-C-methyl-D-erythritol 2,4-cyclodiphosphate) synthetase, also known as YgbB. It is an enzyme in the non-mevalonate pathway of isoprenoid synthesis. Isoprenoids are essential in all organisms, and can also be synthesized through the mevalonate pathway. The non-mevolante route is used by many bacteria and human pathogens, including Mycobacterium tuberculosis and Plasmodium falciparum. This route appears to involve seven enzymes. MECDP synthetase catalyses the intramolecular attack by a phosphate group on a diphosphate, with cytidine monophosphate (CMP) acting as the leaving group to give the cyclic diphosphate product MEDCP. The enzyme is a trimer with three active sites shared between adjacent copies of the protein. The enzyme also has two metal binding sites, the metals playing key roles in catalysis[ 1 ].

A number of proteins from eukaryotes and prokaryotes are bifunctional proteins with an N-terminal IspD domain and a C-terminal IspF domain [ 2 ].

Structurally, IpsF forms trimers with three closely packed beta-sheets.

1. Structure and catalytic mechanism of 2-C-methyl-D-erythritol 2,4-cyclodiphosphate (MECDP) synthase, an enzyme in the non-mevalonate pathway of isoprenoid synthesis. Acta Crystallogr. D Biol. Crystallogr. 59, 23-31
2. Biosynthesis of isoprenoids: a bifunctional IspDF enzyme from Campylobacter jejuni. Eur. J. Biochem. 271, 3028-35