Analysis of the conformational heterogeneity of the Rieske iron-sulfur protein in complex III₂ by cryo-EM.

ABSTRACT: Movement of the Rieske domain of the iron-sulfur protein is essential for intramolecular electron transfer within complex III₂ (CIII₂) of the respiratory chain as it bridges a gap in the cofactor chain towards the electron acceptor cytochrome c. We present cryo-EM structures of CIII₂ from Yarrowia lipolytica at resolutions up to 2.0 Å under different conditions, with different redox states of the cofactors of the high-potential chain. All possible permutations of three primary positions were observed, indicating that the two halves of the dimeric complex act independently. Addition of the substrate analogue decylubiquinone to CIII₂ with a reduced high-potential chain increased the occupancy of the Q_o site. The extent of Rieske domain i

SUBMITTER: Wieferig JP 

PROVIDER: S-EPMC9812224 | biostudies-literature | 2023 Jan

REPOSITORIES: biostudies-literature