8H5E

Crystal structure of the MgtE TM domain in complex with Ca2+ ions at 2.5 angstrom resolution

Summary for 8H5E

• Entry DOI: 10.2210/pdb8h5e/pdb
• Descriptor: Magnesium transporter MgtE, (2R)-2,3-dihydroxypropyl (9Z)-octadec-9-enoate, CALCIUM ION, ... (4 entities in total)
• Functional Keywords: channels, transport protein
• Biological source: Thermus thermophilus
• Total number of polymer chains: 2
• Total formula weight: 40693.01

Authors

Teng, X.,Sheng, D.,Hattori, M. (deposition date: 2022-10-13, release date: 2022-12-07, Last modification date: 2023-11-29)

Primary citation

Teng, X.,Sheng, D.,Wang, J.,Yu, Y.,Hattori, M.
Ion selectivity mechanism of the MgtE channel for Mg 2+ over Ca 2 .
Iscience, 25:105565-105565, 2022

PubMed Abstract: MgtE is a Mg-selective ion channel whose orthologs are widely distributed from prokaryotes to eukaryotes, including humans, and are important participants in the maintenance of cellular Mg homeostasis. The previous high-resolution structure determination of the MgtE transmembrane (TM) domain in complex with Mg ions revealed a recognition mechanism of MgtE for Mg ions. In contrast, the previous Ca-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 ions. Here, we showed that the metal-binding site of the MgtE TM domain binds to Mg ∼500-fold more strongly than to Ca. We then determined the crystal structure of the MgtE TM domain in complex with Ca ions at a higher resolution (2.5 Å resolution), revealing hexahydrated Ca. These results provide mechanistic insights into the ion selectivity of MgtE for Mg over Ca.

PubMed: 36465111
DOI: 10.1016/j.isci.2022.105565

Experimental method

X-RAY DIFFRACTION (2.5 Å)