DMAC2L is a mitochondrial protein involved in regulating ATP synthase function and assembly. As a component of the distal membrane arm of mitochondrial complex I, DMAC2L is essential for proper assembly and stability of the respiratory chain machinery 1. The protein facilitates efficient proton (H+) conduction through ATP synthase by blocking alternative proton leak pathways, thereby optimizing energy coupling during ATP synthesis 2. DMAC2L locates to the mitochondrial inner membrane and operates within the mitochondrial oxidative phosphorylation system, which generates the transmembrane proton gradient required for ATP production. By preventing futile proton recycling, DMAC2L enhances the efficiency of energy-driven ATP synthesis catalysis. Given its role in complex I assembly and function, DMAC2L dysfunction could contribute to mitochondrial diseases, as complex I malfunction is associated with various pathological conditions including neurodegeneration and metabolic dysfunction 1. The gene's location on chromosome 14 and its structural role in the distal membrane arm suggest it represents a conserved accessory subunit critical for maintaining respiratory chain integrity and cellular energy homeostasis.