Figure 6.

Effect of artificial scaffolding configuration on hydrogen production from the synthetic circuit. A.) Positional effects of ferredoxin targeting to artificial scaffold on hydrogen production. B.) Circuit efficiency is dependent upon length of flexible linker connecting ferredoxin (FD) to scaffolding. C.) Modulation of ferredoxin to hydrogenase ratio on scaffold affects hydrogen production, with decreasing yield observed at higher ferredoxin:hydrogenase ratios. D.) Direct fusion of ferredoxins to one another yields diminishing hydrogen production with increased numbers of fused ferredoxin proteins.