CCB complexes after BN-PAGE of digitonin-solubilized membranes. Same strains are shown as in Fig. 2. Digitonin-solubilized proteins were separated in the first dimension by BN-PAGE and in the second dimension by SDS-PAGE, and analyzed by ECL immunodetection. The positions of the molecular weight markers are indicated: thyroglobulin, 669 kD; ferritin, 440 kD; aldolase, 158 kD; conalbumin, 75 kD; and ovalbumin, 43 kD. The CCB2/CCB4 heterodimer is circled. CCB2/CCB4/CCB3 comigration is indicated by a solid box. CCB1/b₆ comigration is indicated by dashed boxes. Cyt b₆ was immunodetected after deprobing α-CCB1 immunodetection, and therefore shows residual detection of CCB1 and cross-reactant below CCB1.