Structural contribution of C-terminal segments of NuoL (ND5) and NuoM (ND4) subunits of complex I from Escherichia coli.

ABSTRACT: The proton-translocating NADH-quinone oxidoreductase (complex I/NDH-1) is a multisubunit enzymatic complex. It has a characteristic L-shaped form with two domains, a hydrophilic peripheral domain and a hydrophobic membrane domain. The membrane domain contains three antiporter-like subunits (NuoL, NuoM, and NuoN, Escherichia coli naming) that are considered to be involved in the proton translocation. Deletion of either NuoL or NuoM resulted in an incomplete assembly of NDH-1 and a total loss of the NADH-quinone oxidoreductase activity. We have truncated the C terminus segments of NuoM and NuoL by introducing STOP codons at different locations using site-directed mutagenesis of chromosomal DNA. Our results suggest an important structural role for the C-terminal segments of both subunits. The

SUBMITTER: Torres-Bacete J 

PROVIDER: S-EPMC3190791 | biostudies-literature | 2011 Sep

REPOSITORIES: biostudies-literature