Functional replacement of yeast flavocytochrome b(2) with bacterial L-lactate dehydrogenase.

Using yeast genetic complementation, we show here that Rhodobacter sphaeroidesl-lactate dehydrogenase can functionally replace flavocytochrome b(2) in Saccharomyces cerevisiae, only when a matrix-targeting signal of flavocytochrome b(2) is fused with the bacterial enzyme. The recombinant l-lactate dehydrogenase may add alternative route of mitochondrial electron transport other than flavocytochrome b(2).