Single particle analysis confirms distal location of subunits NuoL and NuoM in Escherichia coli complex I Journal Article


Author(s): Baranova, Ekaterina A; Morgan, David J; Sazanov, Leonid A
Article Title: Single particle analysis confirms distal location of subunits NuoL and NuoM in Escherichia coli complex I
Affiliation
Abstract: Respiratory complex I catalyses the transfer of electrons from NADH to quinone coupled to the translocation of protons across the membrane. The mechanism of coupling and the structure of the complete enzyme are not known. The membrane domain of the complex contains three similar antiporter-like subunits NuoL/M/N, probably involved in proton pumping. We have previously shown that subunits NuoL/M can be removed from the rest of the complex, suggesting their location at the distal end of the membrane domain. Here, using electron microscopy and single particle analysis, we show that subunits NuoL and M jointly occupy a distal half of the membrane domain, separated by about 10 nm from the interface with the peripheral arm. This indicates that coupling mechanism of complex I is likely to involve long range conformational changes.
Keywords: membrane protein; Complex I; NADH:ubiquinone oxidoreductase; Respiratory chain; Single particle analysis
Journal Title: Journal of Structural Biology
Volume: 159
Issue 2 SPEC. ISS.
ISSN: 1095-8657
Publisher: Academic Press  
Date Published: 2007-08-01
Start Page: 238
End Page: 242
DOI: 10.1016/j.jsb.2007.01.009
Open access: no