Applied Microbiology and Biotechnology

, Volume 89, Issue 1, pp 17–25

Biotechnological potential of the ethylmalonyl-CoA pathway

Mini-Review

DOI: 10.1007/s00253-010-2873-z

Cite this article as:
Alber, B.E. Appl Microbiol Biotechnol (2011) 89: 17. doi:10.1007/s00253-010-2873-z

Abstract

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.

Keywords

Ethylmalonyl-CoA pathwayGlyoxylate cycleClaisen condensationThioesteraseCrotonyl-CoA carboxylase/reductase2-Methylfumaryl-CoA

Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  1. 1.The Department of MicrobiologyOhio State UniversityColumbusUSA