a 5-methoxy-2-methyl-3-(all-trans-polyprenyl)benzene-1,4-diol + A <=> a 5-methoxy-2-methyl-3-(all-trans-polyprenyl)benzoquinone + AH2
a 5-methoxy-2-methyl-3-(all-trans-polyprenyl)benzene-1,4-diol + a <=> a 5-methoxy-2-methyl-3-(all-trans-polyprenyl)benzoquinone + ah2