Biosynthesis of α-Tocopherol and Plastoquinone-9 in spinach chloroplasts

Prenylation and methylation reaction in al biosynthesis is localized in the envelope membranes of the chloroplasts, while PQ-9 biosynthesis takes place in the envelope membranes and also in the thylakoid membranes. The sequence in a-T biosynthesis in spinach is (see also Figure 1): Homogentisate + Phytyl-PP —> Me-6-PQH?—> 2,3-Me2PQH?—>γ J ->a T ; for the PQ-9 biosynthesis it is: Homogentisate + Solanesyf-PP4-> Me-6-SQH2—> PQH2