In enzymology, a biotin—[methylmalonyl-CoA-carboxytransferase] ligase (EC 6.3.4.9) is an enzyme that catalyzes the chemical reaction

ATP + biotin + apo-[methylmalonyl-CoA:pyruvate carboxytransferase] ${\displaystyle \rightleftharpoons }$ AMP + diphosphate + [methylmalonyl-CoA:pyruvate carboxytransferase]

The 3 substrates of this enzyme are ATP, biotin, and [[apo-[methylmalonyl-CoA:pyruvate carboxytransferase]]], whereas its 3 products are AMP, diphosphate, and methylmalonyl-CoA:pyruvate carboxytransferase.

This enzyme belongs to the family of ligases, specifically those forming generic carbon-nitrogen bonds. The systematic name of this enzyme class is biotin:apo[methylmalonyl-CoA:pyruvate carboxytransferase] ligase (AMP-forming). This enzyme participates in biotin metabolism.

• Lane MD, Young DL, Lynen F (1964). "The enzymatic synthesis of holotranscarboxylase from apotranscarboxylase and (+)-biotin. I. Purification of the apoenzyme and synthetase; characteristics of the reaction". J. Biol. Chem. 239: 2858–2864.