Premium
Amino acid residues associated with cluster N3 in the NuoF subunit of the proton‐translocating NADH‐quinone oxidoreductase from Escherichia coli
Author(s) -
Velazquez Isabel,
Nakamaru-Ogiso Eiko,
Yano Takahiro,
Ohnishi Tomoko,
Yagi Takao
Publication year - 2005
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2005.05.005
Subject(s) - oxidoreductase , escherichia coli , protein subunit , cysteine , biochemistry , chemistry , amino acid , quinone , peptide sequence , biology , mutagenesis , stereochemistry , enzyme , gene , mutation
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 351 Cx 2 Cx 2 Cx 40 C 398 motif.