Methyl-coenzyme M reductase (MCR) (MCR)

Methyl-coenzyme M reductase (MCR) is the rate-limiting enzyme responsible for the biological production of methane in methanogenic archaea and its anaerobic oxidation in methanotrophic archaea [10, 11]. It is a complex nickel-containing enzyme that utilizes the unique cofactor F430 to catalyze the reduction of methyl-coenzyme M using coenzyme B as the electron donor [12, 15]. In the context of global sustainability, MCR is a primary target for agricultural biotechnology aimed at reducing enteric methane emissions from ruminant livestock, which account for a significant portion of anthropogenic greenhouse gases [1, 7]. Modulating MCR activity not only mitigates climate impact but also improves animal feed efficiency by redirecting metabolic energy that would otherwise be lost as methane [4, 8]. Small molecule inhibitors such as 3-nitrooxypropanol (3-NOP) have been developed to specifically target the MCR active site, effectively inactivating the enzyme by oxidizing its nickel center [1, 4]. While MCR is not a target for human clinical therapy, its role in environmental health and industrial methane management makes it a critical focus for biotech innovation [10, 13].

Other names

Coenzyme-B sulfoethylthiotransferaseMethyl-SCoM reductaseMCR

Inhibition of the final step of methanogenesis by oxidizing the active site Ni(I) ion to an inactive state or by competitive inhibition at the methyl-coenzyme M binding site.