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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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| S-SCDT-EMBOJ-2019-104369 | biostudies-other

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