Fig. 6.

Proteins associated with subunits b and j in HEK293T-Δδ cells. Quantitative mass spectrometry of affinity purified FLAG-Strep II tagged subunit b (bT) and subunit j (jT) and associated proteins. SILAC-labeled HEK293T-Δδ Flp-In T-REx cells individually overexpressing the tagged proteins were grown separately, and combined and mitoplast samples prepared by a mild digitonin treatment. Proteins in mitoplast samples were extracted using digitonin at a higher detergent:protein ratio of 12:1 (g/g), and tagged plus associated proteins were purified by Strep II affinity chromatography. The experiment was performed twice with reciprocal SILAC labeling orientations. ■, tagged proteins. , ATP synthase subunits. , Other proteins. Each data point corresponds to the abundance ratio of an identified protein from the two complementary experiments. The data for all of the identified proteins are given in Datasets S9–S11.