Acetone and butanone metabolism of the denitrifying bacterium "Aromatoleum aromaticum" demonstrates novel biochemical properties of an ATP-dependent aliphatic ketone carboxylase.

ABSTRACT: The anaerobic and aerobic metabolism of acetone and butanone in the betaproteobacterium "Aromatoleum aromaticum" is initiated by their ATP-dependent carboxylation to acetoacetate and 3-oxopentanoic acid, respectively. Both reactions are catalyzed by the same enzyme, acetone carboxylase, which was purified and characterized. Acetone carboxylase is highly induced under growth on acetone or butanone and accounts for at least 5.5% of total cell protein. The enzyme consists of three subunits of 85, 75, and 20 kDa, respectively, in a (αβγ)(2) composition and contains 1 Zn and 2 Fe per heterohexamer but no organic cofactors. Chromatographic analysis of the ATP hydrolysis products indicated that ATP was exclusively cleaved to AMP and 2 P(i). The stoichiometry was determined to be 2 ATP consumed pe

SUBMITTER: Schuhle K 

PROVIDER: S-EPMC3256595 | biostudies-literature | 2012 Jan

REPOSITORIES: biostudies-literature