1.2.1.76 down approximately 10fold downregulated in presence of acetate, 4-hydroxybutyrate, succinate or pyruvate -, 727749 1.2.1.76 up extracts of autotrophically grown cells exhibit an NADPH-dependent succinyl-CoA reductase activity of 200 nM/min*mg of soluble protein, whereas extracts of heterotrophically grown cells exhibit an activity of 10 nM/min*mg of protein 698628