Extended Data Fig. 3: Conformations of the Arabidopsis I + III₂ supercomplex.

Confromation 1 and 2 with their corresponding overlays on the right. a, View from the plane of the inner mitochondrial membrane indicating the angle between the peripheral and membrane arm of complex I in the two resolved, slightly different conformations of the I + III₂ supercomplex. The angle is 106° in conformation 1 and 108° in confromation 2. The ferredoxin subunit of the bridge domain (C1-FDX) is present and well-defined in both conformations (magenta insets; complex III₂ removed for clarity). b, An end-on view of the supercomplex shows that the peripheral arm tilts by 3 to 5° and C III₂ by 3 to 7 ° relative to the membrane normal (dotted lines). c, A view from the opposite direction reveals that the membrane plane of complex III₂ tilts by 6° or 10° relative to the membrane plane of complex I (dotted line). The panels on the right show conformation 1 in orange and conformation 2 in blue. The inner mitochondrial membrane is shown in grey. The two confromations were obtained by focused 3D classification (Supplementary Figs. 2 and 4; Supplementary Tables 1 and 2).