7QRU

Structure of Bacillus pseudofirmus Mrp antiporter complex, monomer

Summary for 7QRU

• Entry DOI: 10.2210/pdb7qru/pdb
• EMDB information: 14124
• Descriptor: Na+/H+ antiporter subunit D, Na+/H+ antiporter subunit A, Na(+)/H(+) antiporter subunit B, ... (9 entities in total)
• Functional Keywords: antiporter, electron transport, complex, membrane protein
• Biological source: Alkalihalophilus pseudofirmus; More
• Total number of polymer chains: 8
• Total formula weight: 235816.76

Authors

Lee, Y. (deposition date: 2022-01-12, release date: 2022-11-09, Last modification date: 2024-07-17)

Primary citation

Lee, Y.,Haapanen, O.,Altmeyer, A.,Kuhlbrandt, W.,Sharma, V.,Zickermann, V.
Ion transfer mechanisms in Mrp-type antiporters from high resolution cryoEM and molecular dynamics simulations.
Nat Commun, 13:6091-6091, 2022

PubMed Abstract: Multiple resistance and pH adaptation (Mrp) cation/proton antiporters are essential for growth of a variety of halophilic and alkaliphilic bacteria under stress conditions. Mrp-type antiporters are closely related to the membrane domain of respiratory complex I. We determined the structure of the Mrp antiporter from Bacillus pseudofirmus by electron cryo-microscopy at 2.2 Å resolution. The structure resolves more than 99% of the sidechains of the seven membrane subunits MrpA to MrpG plus 360 water molecules, including ~70 in putative ion translocation pathways. Molecular dynamics simulations based on the high-resolution structure revealed details of the antiport mechanism. We find that switching the position of a histidine residue between three hydrated pathways in the MrpA subunit is critical for proton transfer that drives gated trans-membrane sodium translocation. Several lines of evidence indicate that the same histidine-switch mechanism operates in respiratory complex I.

PubMed: 36241630
DOI: 10.1038/s41467-022-33640-y

Experimental method

ELECTRON MICROSCOPY (2.24 Å)