TY  - JOUR
A1  - Lee, Yongchan
A1  - Haapanen, Outi
A1  - Altmeyer, Anton
A1  - Kühlbrandt, Werner
A1  - Sharma, Vivek
A1  - Zickermann, Volker
T1  - Ion transfer mechanisms in Mrp-type antiporters from high resolution cryoEM and molecular dynamics simulations
T2  - Nature Communications
N2  - 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.
Y1  - 2022
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/73413
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-734132
VL  - 13
IS  - Article number: 6091
PB  - Nature Publishing Group
CY  - London
ER  -