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How inter-subunit contacts in the membrane domain of complex I affect proton transfer energetics.

ABSTRACT: The respiratory complex I is a redox-driven proton pump that employs the free energy released from quinone reduction to pump protons across its complete ca. 200?Å wide membrane domain. Despite recently resolved structures and molecular simulations, the exact mechanism for the proton transport process remains unclear. Here we combine large-scale molecular simulations with quantum chemical density functional theory (DFT) models to study how contacts between neighboring antiporter-like subunits in the membrane domain of complex I affect the proton transfer energetics. Our combined results suggest that opening of conserved Lys/Glu ion pairs within each antiporter-like subunit modulates the barrier for the lateral proton transfer reactions. Our work provides a mechanistic suggestion for key coupling effects in the long-range force propagation process of complex I.

SUBMITTER: Di Luca A

PROVIDER: S-EPMC6932872 | biostudies-literature | 2018 Sep

REPOSITORIES: biostudies-literature

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How inter-subunit contacts in the membrane domain of complex I affect proton transfer energetics.

Di Luca Andrea A Mühlbauer Max E ME Saura Patricia P Kaila Ville R I VRI

Biochimica et biophysica acta. Bioenergetics 20180605 9

The respiratory complex I is a redox-driven proton pump that employs the free energy released from quinone reduction to pump protons across its complete ca. 200 Å wide membrane domain. Despite recently resolved structures and molecular simulations, the exact mechanism for the proton transport process remains unclear. Here we combine large-scale molecular simulations with quantum chemical density functional theory (DFT) models to study how contacts between neighboring antiporter-like subunits in ...[more]

PMID: 29883589

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