Glyoxylate Formation from Mesaconyl-CoA and Its Related Reactions in a Methanol-Utilizing Bacterium, Protaminobacter ruber

Abstract

A methanol-utilizing bacterium, Protaminobacter ruber, was shown to assimilate methanol via the serine pathway. As enzyme systems which generate glyoxylate in the serine pathway, P. ruber had malate lyase activity but lacked isocitrate lyase activity.
The cell-free extracts of P. ruber catalyzed the condensation reaction between glyoxylate and propionyl-coenzyme A (CoA). The reaction product was identified as mesaconate and considered to be formed as its CoA derivative. Furthermore, mesaconyl-CoA could be cleaved to glyoxylate and propionyl-CoA. Propionyl-CoA was converted into succinyl-CoA via sequential reactions of propionyl-CoA carboxylase and methylmalonyl-CoA mutase.