Insights into the unique carboxylation reactions in the metabolism of propylene and acetone.

Insights into the unique carboxylation reactions in the metabolism of propylene and acetone. Biochem J. 2020 Jun 12;477(11):2027-2038 Authors: Mus F, Wu HH, Alleman AB, Shisler KA, Zadvornyy OA, Bothner B, Dubois JL, Peters JW Abstract Alkenes and ketones are two classes of ubiquitous, toxic organic compounds in natural environments produced in several biological and anthropogenic processes. In spite of their toxicity, these compounds are utilized as primary carbon and energy sources or are generated as intermediate metabolites in the metabolism of other compounds by many diverse bacteria. The aerobic metabolism of some of the smallest and most volatile of these compounds (propylene, acetone, isopropanol) involves novel carboxylation reactions resulting in a common product acetoacetate. Propylene is metabolized in a four-step pathway involving five enzymes where the penultimate step is a carboxylation reaction catalyzed by a unique disulfide oxidoreductase that couples reductive cleavage of a thioether linkage with carboxylation to produce acetoacetate. The carboxylation of isopropanol begins with conversion to acetone via an alcohol dehydrogenase. Acetone is converted to acetoacetate in a single step by an acetone carboxylase which couples the hydrolysis of MgATP to the activation of both acetone and bicarbonate, generating highly reactive intermediates that are condensed into acetoacetate at a Mn2+ containing the active site. Aceto...
Source: The Biochemical Journal - Category: Biochemistry Authors: Tags: Biochem J Source Type: research