FIGURE 3.

CNAP-tagged Coq proteins co-precipitate several other Coq proteins. W303, CNAP3, CNAP6, and CNAP9 purified mitochondria (15 mg of protein) were solubilized with digitonin and subjected to tandem affinity purification with Ni-NTA resin (Qiagen) followed by anti-PC-agarose (Roche). Samples were separated on 12% SDS-PAGE gels followed by transfer to PVDF membranes for immunoblotting with antisera to the designated yeast polypeptides. 25 μg of mitochondria protein were analyzed for each strain (M), and 2.5% of the first anti-PC elution (E1) volume was loaded per strain (25 μl). Arrows denote each tagged protein in their respective blots. The predominant band in the Coq3 blot detected in the mitochondrial samples represents a background protein and not Coq3, accounting for its presence in CNAP3 mitochondria.