Sequencing and the alignment of structural genes in the nqr operon encoding the Na(+)-translocating NADH-quinone reductase from Vibrio alginolyticus.

We previously cloned a part of nqr operon encoding the Na(+)-translocating NADH-quinone reductase (NQR) from the marine Vibrio alginolyticus [Hayashi et al., FEBS Lett. 356 (1994) 330-332]. From its nucleotide sequences, four consecutive open reading frames (ORF) encoding the gamma-subunit (27.7 kDa), two unidentified ORFs of 22.6 kDa and 21.5 kDa, and the beta-subunit (45.3 kDa) were recognized. The gene encoding the alpha-subunit was located upstream, and together with the recent report by Beattie et al. [FEBS Lett. 356 (1994) 333-338], the nqr operon was found to be constructed from six consecutive structural genes, where nqr1, nqr3 and nqr6 correspond to the alpha-, gamma-, and beta-subunits, respectively, of the NQR complex.