In enzymology, an acetone carboxylase () is an enzyme that catalyzes the chemical reaction
The 4 substrates of this enzyme are acetone, CO<sub>2</sub>, ATP, and H<sub>2</sub>O, whereas its 3 products are acetoacetate, AMP, and phosphate.
This enzyme belongs to the family of ligases, specifically those forming carbon-carbon bonds. The systematic name of this enzyme class is acetone:carbon-dioxide ligase (AMP-forming).