Figure 2.

Proposed role of Rcf1 in the regulation of S. cerevisiae cytochrome c oxidase assembly and activity. (a) Schematic view of the yeast S. cerevisiae modular cytochrome c oxidase assembly pathway [21], depicting the role of Rcf1. Rcf1 interacts with the Cox3 and Cox13 in the Cox3-assembly module and promotes its incorporation into the CIV assembly line to join the assembled Cox1 + Cox2 module. The presence of Rcf1 facilitates the incorporation of Cox12. The figure was generated with PyMOL using the S. cerevisiae cytochrome c oxidase cryo-EM structure PDB 6YMY [57]. Rcf1 was incorporated as a green box, interacting with Cox3 and Cox13 as shown by biochemical studies. (b) Structure of the S. cerevisiae hypoxic respiratory SC III₂–IV containing the Cox5 hypoxic isoform Cox5b and Rcf2 (PDB 6T15) [34].