<p>4-diphosphocytidyl-2C-methyl-D-erythritol synthase, a bacterial ispD protein, catalyzes the third step of the deoxyxylulose-5-phosphate pathway (DXP) of isoprenoid biosynthesis; the formation of 4-diphosphocytidyl-2C-methyl-D-erythritol from CTP and 2C-methyl-D-erythritol 4-phosphate [<cite idref="PUB00011033"/>]. The isoprenoid pathway is a well known target for anti-infective drug development [<cite idref="PUB00043297"/>, <cite idref="PUB00043298"/>].</p><p>This entry represents a pattern that identifies IspD. The pattern is centred on a central conserved region that contains a conserved Asp and Arg residues. </p>