Download MendeleyNovel Mg 2+ binding sites in the cytoplasmic domain of the MgtE Mg 2+ channels revealed by X-ray crystal structures.
Wang, M., Zhao, Y., Hayashi, Y., Ito, K., Hattori, M.(2023) Acta Biochim Biophys Sin (Shanghai) 55: 683-690
- PubMed: 37097058
- DOI: https://doi.org/10.3724/abbs.2023067
- Primary Citation of Related Structures:
8GPS, 8GPV - PubMed Abstract:
MgtE is a Mg 2+ -selective channel regulated by the intracellular Mg 2+ concentration. MgtE family proteins are highly conserved in all domains of life and contribute to cellular Mg 2+ homeostasis. In humans, mutations in the SLC41 proteins, the eukaryotic counterparts of the bacterial MgtE, are known to be associated with various diseases. The first MgtE structure from a thermophilic bacterium, Thermus thermophilus , revealed that MgtE forms a homodimer consisting of transmembrane and cytoplasmic domains with a plug helix connecting the two and that the cytoplasmic domain possesses multiple Mg 2+ binding sites. Structural and electrophysiological analyses revealed that the dissociation of Mg 2+ ions from the cytoplasmic domain induces structural changes in the cytoplasmic domain, leading to channel opening. Thus, previous works showed the importance of MgtE cytoplasmic Mg 2+ binding sites. Nevertheless, due to the limited structural information on MgtE from different species, the conservation and diversity of the cytoplasmic Mg 2+ binding site in MgtE family proteins remain unclear. Here, we report crystal structures of the Mg 2+ -bound MgtE cytoplasmic domains from two different bacterial species, Chryseobacterium hispalense and Clostridiales bacterium , and identify multiple Mg 2+ binding sites, including ones that were not observed in the previous MgtE structure. These structures reveal the conservation and diversity of the cytoplasmic Mg 2+ binding site in the MgtE family proteins.
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.
