title: Amino acid residues associated with cluster N3 in the NuoF subunit of the proton-translocating NADH-quinone oxidoreductase from Escherichia coli.
abstract: The NuoF subunit, which harbors NADH-binding site, of Escherichia coli NADH-quinone oxidoreductase (NDH-1) contains five conserved cysteine residues, four of which are predicted to ligate cluster N3. To determine this coordination, we overexpressed and purified the NuoF subunit and NuoF+E subcomplex in E. coli. We detected two distinct EPR spectra, arising from a [4Fe-4S] cluster (g(x,y,z)=1.90, 1.95, and 2.05) in NuoF, and a [2Fe-2S] cluster (g(x,y,z)=1.92, 1.95, and 2.01) in NuoE subunit. These clusters were assigned to clusters N3 and N1a, respectively. Based on the site-directed mutagenesis experiments, we identified that cluster N3 is ligated to the 351Cx2Cx2Cx40C398 motif.
authors.affiliation: Division of Biochemistry, Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA.
authors.forename: Isabel
authors.initials: I
authors.lastname: Velazquez
authors.forename: Eiko
authors.initials: E
authors.lastname: Nakamaru-Ogiso
authors.forename: Takahiro
authors.initials: T
authors.lastname: Yano
authors.forename: Tomoko
authors.initials: T
authors.lastname: Ohnishi
authors.forename: Takao
authors.initials: T
authors.lastname: Yagi
mesh_terms: D000596:Amino Acids / Q000378:metabolism*; D004578:Electron Spin Resonance Spectroscopy; D004579:Electron Transport; D004926:Escherichia coli / Q000201:enzymology*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D007501:Iron / Q000494:pharmacology; D021122:Protein Subunits / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D011522:Protons; D011808:Quinone Reductases / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D013455:Sulfur / Q000494:pharmacology
chemical_list: D000596:Amino Acids; D029968:Escherichia coli Proteins; D021122:Protein Subunits; D011522:Protons; D013455:Sulfur; D007501:Iron; C041831:NADH dehydrogenase (quinone); C502197:NuoF protein, E coli; D011808:Quinone Reductases