Solubilized mitochondria from MITRAC15FLAG-expressing cells were first subjected to native anti-FLAG immunoisolation (Total 0.1 %, Eluate 10 %, lane 4). Purified complexes were applied to anti-MITRAC12 immunoisolation (Eluates 100 %, lane 5). All samples were analyzed by SDS-PAGE and immunoblotting. 