Role of ubiquinone in hydrogen-dependent electron transport in Rhizobium japonicum

Abstract

Direct evidence for the involvement of ubiquinone in H2 oxidation by Rhizobium japonicum was demonstrated; H2 reduced ca. 80% of the extractable ubiquinone. The inhibitor 2-n-heptyl-4-hydroxyquinoline-N-oxide blocked electron transport at a site between ubiquinone and the cytochromes. The results showed that no cytochrome component mediates electron flow from hydrogen to ubiquinone.