An iron-sulfur protein that contains a [4Fe-4S] cluster [1,2]. 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 .
simultaneous expression of (E)-4-hydroxy-3-methylbut-2-enyl diphosphate synthase and ferredoxin I in Escherichia coli shows strong interaction of both proteins. Ferredoxin I is able to transfer electrons to the synthase