Steps Toward Heterologous Biosynthesis of Coenzyme M

Coenzyme M (CoM) is a key cofactor in the biological production of methane and in the breakdown of alkenes and epoxides. CoM-dependent metabolic pathways are of interest because they could be used for the bioconversion of unconventional and harmful substrates like alkenes to biofuels and other useful chemicals. However, these useful metabolic pathways cannot currently be implemented in typical metabolic workhorses such as Escherichia coli since these organisms do not naturally produce CoM. This work demonstrates production of the first two intermediates in the bacterial CoM biosynthesis pathway in E. coli. Predicted CoM biosynthesis enzymes from Xanthobacter autotrophicus Py2 and their homologs from Bacillus subtilis or E. coli were expressed in E. coli. Pathway intermediates were detected in cellular extracts from strains containing enzymes from B. subtilis and X. autotrophicus Py2. Additionally, the first enzyme of the pathway, which has never been previously characterized, was characterized in vitro to obtain kinetic parameters. This work is significant because it achieves steps in CoM biosynthesis in E. coli, which is important for enabling use of a broader range of substrates in this heterologous system.