A Lumenal Loop Associated with Catalytic Asymmetry in Plant Vacuolar H⁺-Translocating Pyrophosphatase.

ABSTRACT: Membrane-integral inorganic pyrophosphatases (mPPases) couple pyrophosphate hydrolysis with H⁺ and Na⁺ pumping in plants and microbes. mPPases are homodimeric transporters with two catalytic sites facing the cytoplasm and demonstrating highly different substrate-binding affinities and activities. The structural aspects of the functional asymmetry are still poorly understood because the structure of the physiologically relevant dimer form with only one active site occupied by the substrate is unknown. We addressed this issue by molecular dynamics (MD) simulations of the H⁺-transporting mPPase of Vigna radiata, starting from its crystal structure containing a close substrate analog (imidodiphosphate, IDP) in both active sites. The MD simulations reveal

SUBMITTER: Anashkin VA 

PROVIDER: S-EPMC8657866 | biostudies-literature | 2021 Nov

REPOSITORIES: biostudies-literature