Download MendeleyIon selectivity mechanism of the MgtE channel for Mg 2+ over Ca 2 .
Teng, X., Sheng, D., Wang, J., Yu, Y., Hattori, M.(2022) iScience 25: 105565-105565
- PubMed: 36465111
- DOI: https://doi.org/10.1016/j.isci.2022.105565
- Primary Citation of Related Structures:
8H5E - PubMed Abstract:
MgtE is a Mg 2+ -selective ion channel whose orthologs are widely distributed from prokaryotes to eukaryotes, including humans, and are important participants in the maintenance of cellular Mg 2+ homeostasis. The previous high-resolution structure determination of the MgtE transmembrane (TM) domain in complex with Mg 2+ ions revealed a recognition mechanism of MgtE for Mg 2+ ions. In contrast, the previous Ca 2+ -bound structure of the MgtE TM domain was determined only at moderate resolution (3.2 Å resolution), which was insufficient to visualize the water molecules coordinated to Ca 2+ ions. Here, we showed that the metal-binding site of the MgtE TM domain binds to Mg 2+ ∼500-fold more strongly than to Ca 2+ . We then determined the crystal structure of the MgtE TM domain in complex with Ca 2+ ions at a higher resolution (2.5 Å resolution), revealing hexahydrated Ca 2+ . These results provide mechanistic insights into the ion selectivity of MgtE for Mg 2+ over Ca 2+ .
Organizational Affiliation:
State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Shanghai Key Laboratory of Bioactive Small Molecules, Department of Physiology and Neurobiology, School of Life Sciences, Fudan University, Shanghai 200438, China.
