Fig. 2

Biosynthesis of coenzyme Q₁₀. Schematic showing the pathway of various metabolic precursors leading to the formation of the quinone head (PHB), the isoprene tail (decaprenyl diphosphate), and the final Coenzyme Q product. Reflected in red are the various enzymatic steps that are rate limiting. UbiC and UbiA are specific genes from E. coli, and Coq2 is from S. cerevisiae. Unlabelled arrows between chorismate and tyrosine and PHB; FPP and decaprenyl diphosphate; and decaprenyl-4-hydrobenzoic acid and coenzyme Q₁₀ denote the presence of multiple steps that have been abbreviated