Tandem and single genes of three membrane-bound nitrate transporters in the nar gene cluster of the moderately halophilic denitrifier, Halomonas halodenitrificans.

We identified the genes encoding the membrane-bound nitrate reductase (Nar) from the moderate halophile, Halomonas halodenitrificans, and examined the structure of the gene cluster. Screening of a H. halodenitrificans genomic DNA library in lambda EMBL3 phage by chromosome walking revealed that the region adjacent to the nor gene cluster encoding nitric oxide (NO) reductase contains three nitrate transporters: tandem narK2 and narK1.