ジャーナル: Elife / 年: 2021 タイトル: Atomic structures of respiratory complex III, complex IV, and supercomplex III-IV from vascular plants. 著者: Maria Maldonado / Fei Guo / James A Letts / 要旨: Mitochondrial complex III (CIII) and complex IV (CIV), which can associate into a higher-order supercomplex (SC III+IV), play key roles in respiration. However, structures of these plant complexes ...Mitochondrial complex III (CIII) and complex IV (CIV), which can associate into a higher-order supercomplex (SC III+IV), play key roles in respiration. However, structures of these plant complexes remain unknown. We present atomic models of CIII, CIV, and SC III+IV from determined by single-particle cryoEM. The structures reveal plant-specific differences in the MPP domain of CIII and define the subunit composition of CIV. Conformational heterogeneity analysis of CIII revealed long-range, coordinated movements across the complex, as well as the motion of CIII's iron-sulfur head domain. The CIV structure suggests that, in plants, proton translocation does not occur via the H channel. The supercomplex interface differs significantly from that in yeast and bacteria in its interacting subunits, angle of approach and limited interactions in the mitochondrial matrix. These structures challenge long-standing assumptions about the plant complexes and generate new mechanistic hypotheses.
EMPIAR-10586 (タイトル: Cryo electron micrographs of digitonin-solubilized, amphipol-stabilized, sucrose-gradient-purified V. radiata mitochondrial membranes - mixed fraction containing CI*, CIII2 and SC III2+IV Data size: 6.7 TB Data #1: Raw movies of mixed sample used for determination of mung bean respiratory CI*, CIII2, CIV and SC III2+IV [micrographs - multiframe])