bims-tricox 2024-02-11 papers

Issue of 2024‒02‒11
two papers selected by
Yash Verma, University of Zurich

Nat Struct Mol Biol. 2024 Feb 05.

Conformational ensemble of yeast ATP synthase at low pH reveals unique intermediates and plasticity in F1-Fo coupling.

Stuti Sharma, Min Luo, Hiral Patel, David M Mueller, Maofu Liao.

Mitochondrial adenosine triphosphate (ATP) synthase uses the proton gradient across the inner mitochondrial membrane to synthesize ATP. Structural and single molecule studies conducted mostly at neutral or basic pH have provided details of the reaction mechanism of ATP synthesis. However, pH of the mitochondrial matrix is slightly acidic during hypoxia and pH-dependent conformational changes in the ATP synthase have been reported. Here we use single-particle cryo-EM to analyze the conformational ensemble of the yeast (Saccharomyces cerevisiae) ATP synthase at pH 6. Of the four conformations resolved in this study, three are reaction intermediates. In addition to canonical catalytic dwell and binding dwell structures, we identify two unique conformations with nearly identical positions of the central rotor but different catalytic site conformations. These structures provide new insights into the catalytic mechanism of the ATP synthase and highlight elastic coupling between the catalytic and proton translocating domains.

DOI: https://doi.org/10.1038/s41594-024-01219-4

Methods Mol Biol. 2024 ;2755 215-226

Evaluation of Oxygen Consumption Rates In Situ.

Anqi Li, Yuan Qin, Ying Zhang, Xiaoqun Zhen, Guohua Gong.

An analysis of the mitochondrial respiration function represented by the oxygen consumption rate is necessary to assess mitochondrial bioenergetics and redox function. This protocol describes two alternative techniques to evaluate mitochondrial respiration function in situ: (1) measure oxygen consumption rates via an electrode; (2) measure oxygen consumption rates via a seahorse instrument. These in situ approaches provide more physiological access to mitochondria to evaluate mitochondrial respiration function in a relatively integrated cellular system.

Keywords: ATP; Mitochondria; Mitochondrial stress test; Oxidative phosphorylation; Oxygen consumption

DOI: https://doi.org/10.1007/978-1-0716-3633-6_16