7RJC

Complex III2 from Candida albicans, inhibitor free, Rieske head domain in intermediate position

Summary for 7RJC

• Entry DOI: 10.2210/pdb7rjc/pdb
• EMDB information: 24482 24483 24484 24485 24486
• Descriptor: Ubiquinol--cytochrome-c reductase subunit, PROTOPORPHYRIN IX CONTAINING FE, UBIQUINONE-10, ... (13 entities in total)
• Functional Keywords: candida albicans, mitochondrial complex iii2, indazole-derivative inhibitor, rieske head domain, membrane protein
• Biological source: Candida albicans (strain SC5314 / ATCC MYA-2876) (Yeast); More
• Total number of polymer chains: 10
• Total formula weight: 259965.38

Authors

Di Trani, J.M.,Rubinstein, J.L. (deposition date: 2021-07-20, release date: 2021-09-15, Last modification date: 2022-01-19)

Primary citation

Di Trani, J.M.,Liu, Z.,Whitesell, L.,Brzezinski, P.,Cowen, L.E.,Rubinstein, J.L.
Rieske head domain dynamics and indazole-derivative inhibition of Candida albicans complex III.
Structure, 30:129-, 2022

PubMed Abstract: Electron transfer between respiratory complexes drives transmembrane proton translocation, which powers ATP synthesis and membrane transport. The homodimeric respiratory complex III (CIII) oxidizes ubiquinol to ubiquinone, transferring electrons to cytochrome c and translocating protons through a mechanism known as the Q cycle. The Q cycle involves ubiquinol oxidation and ubiquinone reduction at two different sites within each CIII monomer, as well as movement of the head domain of the Rieske subunit. We determined structures of Candida albicans CIII by cryoelectron microscopy (cryo-EM), revealing endogenous ubiquinone and visualizing the continuum of Rieske head domain conformations. Analysis of these conformations does not indicate cooperativity in the Rieske head domain position or ligand binding in the two CIIIs of the CIII dimer. Cryo-EM with the indazole derivative Inz-5, which inhibits fungal CIII and is fungicidal when administered with fungistatic azole drugs, showed that Inz-5 inhibition alters the equilibrium of Rieske head domain positions.

PubMed: 34525326
DOI: 10.1016/j.str.2021.08.006

Experimental method

ELECTRON MICROSCOPY (3.3 Å)