3rkg
From Proteopedia
Structural and Functional Characterization of the Yeast Mg2+ Channel Mrs2
Structural highlights
Function[MRS2_YEAST] High-conductance magnesium-selective channel that mediates the influx of magnesium into the mitochondrial matrix. Essential for the splicing of mRNA group II introns in mitochondria by affecting mitochondrial magnesium concentrations, which are critical for group II intron splicing. It also suppresses a variety of mitochondrial intron mutations and its absence may disturb the assembly of mitochondrial membrane complexes.[1] [2] [3] [4] Publication Abstract from PubMedMg(2+) translocation across cellular membranes is crucial for a myriad of physiological processes. Eukaryotic Mrs2 transporters are distantly related to the major bacterial Mg(2+) transporter CorA, the structure of which displays a bundle of giant alpha-helices forming a long pore that extends beyond the membrane before widening into a funnel-shaped cytosolic domain. Here, a functional and structural analysis of the regulatory domain of the eukaryotic Mg(2+) channel Mrs2 from the yeast inner mitochondrial membrane is presented using crystallography, genetics, biochemistry and fluorescence spectroscopy. Surprisingly, the fold of the Mrs2 regulatory domain bears notable differences compared with the related bacterial channel CorA. Nevertheless, structural analysis showed that analogous residues form functionally critical sites, notably the hydrophobic gate and the Mg(2+)-sensing site. Validation of candidate residues was performed by functional studies of mutants in isolated yeast mitochondria. Measurements of the Mg(2+) influx into mitochondria confirmed the involvement of Met309 as the major gating residue in Mrs2, corresponding to Met291 in CorA. Structural and functional characterization of the N-terminal domain of the yeast Mg(2+) channel Mrs2.,Khan MB, Sponder G, Sjoblom B, Svidova S, Schweyen RJ, Carugo O, Djinovic-Carugo K Acta Crystallogr D Biol Crystallogr. 2013 Sep 1;69(Pt 9):1653-64. doi:, 10.1107/S0907444913011712. Epub 2013 Aug 15. PMID:23999289[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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