. "Forms, in the reverse direction, part of an alternative non-mevalonate pathway for isoprenoid biosynthesis that is found in most bacteria and in plant chloroplasts." . "The enzyme from the plant Arabidopsis thaliana is active with photoreduced 5-deazaflavin but not with the flavodoxin/flavodoxin reductase/NADPH system that can be used as an electron donor by Escherichia coli." . "Metabolites derived from isoprenoids play important roles in systems such as electron transport, photosynthesis, plant defense responses, hormonal regulation of development and membrane fluidity." . . . "4-hydroxy-3-methylbut-2-en-1-yl diphosphate synthase" . "(E)-4-hydroxy-3-methylbut-2-enyl diphosphate synthase" . "(E)-4-hydroxy-3-methylbut-2-enyl-diphosphate synthase" . . "(E)-4-hydroxy-3-methylbut-2-en-1-yl diphosphate + H(2)O + 2 oxidized ferredoxin = 2-C-methyl-D-erythritol 2,4-cyclodiphosphate + 2 reduced ferredoxin." . "Iron-sulfur" .