Participation of MEP-dependent isoprene biosynthesis pathway into two modules.

<p>Gene symbols and the enzymes they encode (all genes were from <i>E. coli</i> except where noted): <i>dxs</i>, DXP synthase; <i>ispC</i>, DXP reductionisomerase; <i>ispD</i>, DXP-ME synthase; <i>ispE</i>, CDP-ME kinase; <i>ispF</i>, MECPP synthase; <i>ispG</i>, HMBPP synthase; <i>ispH</i>, HMBPP reductase; <i>idi</i>, IPP isomerase; <i>ispS</i>, isoprene synthase (<i>P. alba</i>). Pathway intermediates: G3P, glyceraldehyde-3-phosphate; DXP, 1-deoxy-D-xylulose 5-phosphate; MEP, 2-<i>C</i>-methyl-D-erythritol 4-phosphate; CDP-ME, 4-diphosphocytidyl-2-<i>C</i>-methyl-D-erythritol; CDP-MEP, 4-diphosphocytidyl-2-<i>C</i>-methyl-D-erythritol 2-phosphate; MECPP, 2-<i>C</i>-methyl-D-erythritol 2,4-cyclopyrophosphate; HMBPP, 1-hydroxy-2-methyl-2-(<i>E</i>)-butenyl 4-pyrophosphate; IPP, isopentenyl pyrophosphate; DMAPP, dimethylallyl pyrophosphate; DHAP, dihydroxyacetone 3-phosphate.