Biotechnological potential of the ethylmalonyl-CoA pathway.
The ethylmalonyl-CoA pathway is central to the carbon metabolism of many α-proteobacteria, like Rhodobacter sphaeroides and Methylobacterium extorquens as well as actinomycetes, like Streptomyces spp. Its function is to convert acetyl-CoA, a central carbon intermediate, to other precursor metabolites for cell carbon biosynthesis. In contrast to the glyoxylate cycle--another widely distributed acetyl-CoA assimilation strategy--the ethylmalonyl-CoA pathway contains many unique CoA-ester intermediates, such as (2R)- and (2S)-ethylmalonyl-CoA, (2S)-methylsuccinyl-CoA, mesaconyl-(C1)-CoA, and (2R, 3S)-methylmalyl-CoA. With this come novel catalysts that interconvert these compounds. Among these unique enzymes is a novel carboxylase that reductively carboxylates crotonyl-CoA, crotonyl-CoA carboxylase/reductase, and (3S)-malyl-CoA thioesterase. The latter represents the first example of a non-Claisen condensation enzyme of the malate synthase superfamily and defines a new class of thioesterases apart from the hotdog-fold and α/β-fold thioesterases. The biotechnological implications of the ethylmalonyl-CoA pathway are tremendous as one looks to tap into the potential of using these new intermediates and catalysts to produce value-added products.
Alber
Birgit E
BE
The Department of Microbiology, Ohio State University, 484 West 12th Ave, Room 417, Columbus, OH, USA. alber.8@osu.edu
D000214:Acyl Coenzyme A / Q000378:metabolism*; D001419:Bacteria / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D053898:Biosynthetic Pathways; D002244:Carbon / Q000378:metabolism; D007218:Industrial Microbiology
D000214:Acyl Coenzyme A; D001426:Bacterial Proteins; C102829:ethylmalonyl-coenzyme A; D002244:Carbon