Roles of subunit NuoL in the proton pumping coupling mechanism of NADH:ubiquinone oxidoreductase (complex I) from Escherichia coli.

ABSTRACT: Respiratory complex I has an L-shaped structure formed by the hydrophilic arm responsible for electron transfer and the membrane arm that contains protons pumping machinery. Here, to gain mechanistic insights into the role of subunit NuoL, we investigated the effects of Mg²⁺, Zn²⁺ and the Na⁺/H⁺ antiporter inhibitor 5-(N-ethyl-N-isopropyl)-amiloride (EIPA) on proton pumping activities of various isolated NuoL mutant complex I after reconstitution into Escherichia coli double knockout (DKO) membrane vesicles lacking complex I and the NADH dehydrogenase type 2. We found that Mg²⁺ was critical for proton pumping activity of complex I. At 2 µM Zn²⁺, proton pumping of the wild-type was selectively inhibited without affecting elec

SUBMITTER: Narayanan M 

PROVIDER: S-EPMC5048018 | biostudies-literature | 2016 Oct

REPOSITORIES: biostudies-literature