L-malyl-coenzyme A/beta-methylmalyl-coenzyme A lyase is involved in acetate assimilation of the isocitrate lyase-negative bacterium Rhodobacter capsulatus.

ABSTRACT: Cell extracts of Rhodobacter capsulatus grown on acetate contained an apparent malate synthase activity but lacked isocitrate lyase activity. Therefore, R. capsulatus cannot use the glyoxylate cycle for acetate assimilation, and a different pathway must exist. It is shown that the apparent malate synthase activity is due to the combination of a malyl-coenzyme A (CoA) lyase and a malyl-CoA-hydrolyzing enzyme. Malyl-CoA lyase activity was 20-fold up-regulated in acetate-grown cells versus glucose-grown cells. Malyl-CoA lyase was purified 250-fold with a recovery of 6%. The enzyme catalyzed not only the reversible condensation of glyoxylate and acetyl-CoA to L-malyl-CoA but also the reversible condensation of glyoxylate and propionyl-CoA to beta-methylmalyl-CoA. Enzyme activity was stimulated

SUBMITTER: Meister M 

PROVIDER: S-EPMC545638 | biostudies-literature | 2005 Feb

REPOSITORIES: biostudies-literature