This gene encodes a member of the acyl-CoA synthetase family of enzymes that activate fatty acids by catalyzing the formation of a thioester linkage between fatty acids and coenzyme A. The encoded protein is localized to mitochondria, has high specificity for malonate and methylmalonate and possesses malonyl-CoA synthetase activity. Mutations in this gene are a cause of combined malonic and methylmalonic aciduria. Alternatively spliced transcript variants have been observed for this gene.