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Hryc CF, Mallampalli VKPS, Bovshik EI, Azinas S, Fan G, Serysheva II, Sparagna GC, Baker ML, Mileykovskaya E, Dowhan W. Structural insights into cardiolipin replacement by phosphatidylglycerol in a cardiolipin-lacking yeast respiratory supercomplex. Nat Commun 2023; 14:2783. [PMID: 37188665 PMCID: PMC10185535 DOI: 10.1038/s41467-023-38441-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 05/03/2023] [Indexed: 05/17/2023] Open
Abstract
Cardiolipin is a hallmark phospholipid of mitochondrial membranes. Despite established significance of cardiolipin in supporting respiratory supercomplex organization, a mechanistic understanding of this lipid-protein interaction is still lacking. To address the essential role of cardiolipin in supercomplex organization, we report cryo-EM structures of a wild type supercomplex (IV1III2IV1) and a supercomplex (III2IV1) isolated from a cardiolipin-lacking Saccharomyces cerevisiae mutant at 3.2-Å and 3.3-Å resolution, respectively, and demonstrate that phosphatidylglycerol in III2IV1 occupies similar positions as cardiolipin in IV1III2IV1. Lipid-protein interactions within these complexes differ, which conceivably underlies the reduced level of IV1III2IV1 and high levels of III2IV1 and free III2 and IV in mutant mitochondria. Here we show that anionic phospholipids interact with positive amino acids and appear to nucleate a phospholipid domain at the interface between the individual complexes, which dampen charge repulsion and further stabilize interaction, respectively, between individual complexes.
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Affiliation(s)
- Corey F Hryc
- Department of Biochemistry and Molecular Biology, McGovern Medical School at the University of Texas Health Science Center, Houston, Texas, USA
| | - Venkata K P S Mallampalli
- Department of Biochemistry and Molecular Biology, Structural Biology Imaging Center, McGovern Medical School at the University of Texas Health Science Center, Houston, Texas, USA
| | - Evgeniy I Bovshik
- Department of Biochemistry and Molecular Biology, McGovern Medical School at the University of Texas Health Science Center, Houston, Texas, USA
| | - Stavros Azinas
- Department of Biochemistry and Molecular Biology, McGovern Medical School at the University of Texas Health Science Center, Houston, Texas, USA
| | - Guizhen Fan
- Department of Biochemistry and Molecular Biology, Structural Biology Imaging Center, McGovern Medical School at the University of Texas Health Science Center, Houston, Texas, USA
| | - Irina I Serysheva
- Department of Biochemistry and Molecular Biology, Structural Biology Imaging Center, McGovern Medical School at the University of Texas Health Science Center, Houston, Texas, USA
| | - Genevieve C Sparagna
- Department of Medicine, Division of Cardiology, University of Colorado Anschutz Medical Campus, Aurora, Colorada, USA
| | - Matthew L Baker
- Department of Biochemistry and Molecular Biology, Structural Biology Imaging Center, McGovern Medical School at the University of Texas Health Science Center, Houston, Texas, USA.
| | - Eugenia Mileykovskaya
- Department of Biochemistry and Molecular Biology, McGovern Medical School at the University of Texas Health Science Center, Houston, Texas, USA.
| | - William Dowhan
- Department of Biochemistry and Molecular Biology, Center for Membrane Biology, McGovern Medical School at the University of Texas Health Science Center, Houston, Texas, USA.
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