Putative mitochondrial ATPase. Plays a role in mitochondrial morphology and mitochondrial protein metabolism. Promotes degradation of excess nuclear-encoded complex IV subunits (COX4I1, COX5A and COX6A1) and normal activity of complexes III and IV of the respiratory chain. Mediates mitochondrial translocation of TP53 and its transcription-independent apoptosis in response to genotoxic stress. Found in several complexes of 140-500 kDa. Interacts with YME1L1. Interacts with COX4I1. Interacts with COX5A. Interacts with TP53; mediates mitochondrial translocation of TP53 in response to genotoxic stress such as mitomycin C treatment. Highly expressed in heart, kidney, and lactating breast. Present at reduced levels in virgin, pregnant, and involuting breast. Expression is elevated during lactation. Belongs to the AFG1 ATPase family.