Molecular mechanism of Mg2+-dependent gating in CorA.

ABSTRACT: CorA is the major transport system responsible for Mg(2+) uptake in bacteria and can functionally substitute for its homologue Mrs2p in the yeast inner mitochondrial membrane. Although several CorA crystal structures are available, the molecular mechanism of Mg(2+) uptake remains to be established. Here we use electron paramagnetic resonance spectroscopy, electrophysiology and molecular dynamic simulations to show that CorA is regulated by cytoplasmic Mg(2+) acting as a ligand and elucidate the basic conformational rearrangements responsible for Mg(2+)-dependent gating. Mg(2+) unbinding at the divalent cation sensor triggers a conformational change that leads to the inward motion of the stalk helix, which propagates to the pore-forming transmembrane helix TM1. Helical tilting and rotation

SUBMITTER: Dalmas O 

PROVIDER: S-EPMC4066822 | biostudies-literature | 2014 Apr

REPOSITORIES: biostudies-literature