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Functional analysis of the conserved hydrophobic gate region of the magnesium transporter CorA

Soňa Svidová1, Gerhard Sponder, Rudolf J Schweyen

  • 1Department of Microbiology, Immunobiology and Genetics, Max F. Perutz Laboratories, University of Vienna, Dr. Bohrgasse 9/4, A-1030 Vienna, Austria.

Biochimica Et Biophysica Acta
|November 16, 2010
PubMed

Insights

The Leu294 residue is crucial for gating magnesium (Mg2+) transport in Thermotoga maritima CorA. Mutations here reveal how amino acid properties influence pore closure and Mg2+ uptake regulation.

Area of Science:

  • Biochemistry
  • Molecular Biology
  • Structural Biology

Background:

  • The CorA protein facilitates magnesium ion (Mg2+) transport across cell membranes.
  • The Leu294 residue in Thermotoga maritima CorA has been hypothesized as the primary gate for Mg2+ transport.

Purpose of the Study:

  • To investigate the role of the Leu294 residue in the gating mechanism of Thermotoga maritima CorA.
  • To determine how specific amino acid substitutions at position 294 affect Mg2+ transport and its regulation.

Main Methods:

  • Site-directed mutagenesis was used to create three mutants at the Leu294 position: Leu294Asp, Leu294Gly, and Leu294Arg.
  • Analysis of pore closure defects and regulation of Mg2+ uptake in the generated mutants.

Main Results:

  • The Leu294Asp and Leu294Gly mutants exhibited defects in pore closure, indicating impaired gating.
  • The Leu294Arg mutant showed defects in both gating and the regulation of Mg2+ uptake.
  • These findings highlight the critical role of Leu294 in controlling the Mg2+ transport pore.

Conclusions:

  • The Leu294 residue is essential for the proper gating of Mg2+ transport mediated by CorA.
  • The charge and structural characteristics of amino acid residues at position 294 significantly influence the gating mechanism and regulatory processes of Mg2+ uptake.

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