Figure 4.

Acquisition of a second fumarate reductase/succinate dehydrogenase by G. metallireducens. (a) The ancestral gene cluster. (b) The gene cluster acquired from a relative of the Chlorobiaceae, located near other acquired genes relevant to central metabolism: an uncharacterized enzyme related to succinyl-CoA synthetase and citrate synthase (Gmet_0305-Gmet_0306) and phosphoenolpyruvate carboxylase (Gmet_0304). Conserved nucleotide sequences (black stripes) were also identified in the two regions.