Key role of quinone in the mechanism of respiratory complex I.

ABSTRACT: Complex I is the first and the largest enzyme of respiratory chains in bacteria and mitochondria. The mechanism which couples spatially separated transfer of electrons to proton translocation in complex I is not known. Here we report five crystal structures of T. thermophilus enzyme in complex with NADH or quinone-like compounds. We also determined cryo-EM structures of major and minor native states of the complex, differing in the position of the peripheral arm. Crystal structures show that binding of quinone-like compounds (but not of NADH) leads to a related global conformational change, accompanied by local re-arrangements propagating from the quinone site to the nearest proton channel. Normal mode and molecular dynamics analyses indicate that these are likely to represent the first st

SUBMITTER: Gutierrez-Fernandez J 

PROVIDER: S-EPMC7434922 | biostudies-literature | 2020 Aug

REPOSITORIES: biostudies-literature