Ion and inhibitor binding of the double-ring ion selectivity filter of the mitochondrial calcium uniporter.

ABSTRACT: The calcium (Ca²⁺) uniporter of mitochondria is a holocomplex consisting of the Ca²⁺-conducting channel, known as mitochondrial calcium uniporter (MCU), and several accessory and regulatory components. A previous electrophysiology study found that the uniporter has high Ca²⁺ selectivity and conductance and this depends critically on the conserved amino acid sequence motif, DXXE (Asp-X-X-Glu) of MCU. A recent NMR structure of the MCU channel from Caenorhabditis elegans revealed that the DXXE forms two parallel carboxylate rings at the channel entrance that seem to serve as the ion selectivity filter, although direct ion interaction of this structural motif has not been addressed. Here, we use a paramagnetic probe, manganese (Mn²⁺), to inves

SUBMITTER: Cao C 

PROVIDER: S-EPMC5389301 | biostudies-literature | 2017 Apr

REPOSITORIES: biostudies-literature