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P-type ATPase magnesium transporter MgtA acts as a dimer

  • 0Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA.
Nature Structural & Molecular Biology +

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June 23, 2025

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June 23, 2025

View abstract on PubMed

Summary

This summary is machine-generated.

This study reveals the structure of the bacterial magnesium (Mg<sup>2+</sup>) transporter MgtA using cryo-EM. The findings illuminate how this essential protein facilitates magnesium ion transport and regulation in bacteria.

Area Of Science

  • Biochemistry
  • Structural Biology
  • Microbiology

Background

  • Magnesium ions (Mg<sup>2+</sup>) are essential for all life.
  • P-type ATPase Mg<sup>2+</sup> importers are crucial for bacterial growth and pathogenesis.
  • The mechanism of Mg<sup>2+</sup> transport by these importers remains largely unknown.

Purpose Of The Study

  • To elucidate the structural basis of Mg<sup>2+</sup> transport by the MgtA protein from Escherichia coli.
  • To gain insights into the mechanism of Mg<sup>2+</sup> uptake and regulation.

Main Methods

  • Cryo-electron microscopy (cryo-EM) to determine high-resolution structures.
  • Biochemical assays, including ATPase activity measurements.
  • Site-directed mutagenesis to investigate protein function.

Main Results

  • High-resolution cryo-EM structures of homodimeric and monomeric MgtA were obtained.
  • An ion, identified as Mg<sup>2+</sup>, was localized within the transmembrane segment.
  • Two cytoplasmic ion-binding sites and the N-terminal tail structure were characterized.

Conclusions

  • The MgtA structure reveals key features facilitating Mg<sup>2+</sup> transport.
  • Dimerization, identified ion-binding sites, and the N-terminal tail play roles in cation transport or regulation.
  • This work provides a structural foundation for understanding bacterial Mg<sup>2+</sup> homeostasis.

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