title: Identification of the functional periplasmic nitrate reductase (nap) gene cluster from the deep-sea denitrifier Pseudomonas sp. strain MT-1.
abstract: The nap gene cluster encoding periplasmic nitrate reductase was identified from Pseudomonas sp. strain MT-1, a deep-sea denitrifier isolated from the Mariana Trench. The ORFs identified were highly homologous with those of Pseudomonas stutzeri, but the cluster included only four ORFs (napDABC), less than those in other organisms. For other bacteria, some additional small ORFs (such as napE, napF, napG, napH, and napK) are found in the nap gene cluster, although their physiological function is still unclear. The soluble fraction of MT-1 grown under denitrifying condition showed significant nitrate reductase activity. This observation suggests that the periplasmic nitrate reductase encoded by the gene cluster identified in this study is functional. The activity was highest when the organism was grown under denitrifying conditions, suggesting that the enzyme participates in dissimilatory nitrite reduction.
authors: Department of Chemistry, College of Humanities and Sciences, Nihon University, Sakurajosui, Tokyo, Japan. htamegai@chs.nihon-u.ac.jp
authors: Hideyuki
authors: H
authors: Tamegai
authors: Eriko
authors: E
authors: Ikeda
authors: Chiaki
authors: C
authors: Kato
authors: Koki
authors: K
authors: Horikoshi
mesh_terms: D005810:Multigene Family; D050901:Nitrate Reductase / Q000235:genetics*; D009573:Nitrites / Q000378:metabolism*; D016366:Open Reading Frames; D010084:Oxidation-Reduction; D033903:Periplasmic Proteins / Q000235:genetics; D011549:Pseudomonas / Q000201:enzymology*; D012623:Seawater / Q000382:microbiology*; D012689:Sequence Homology, Nucleic Acid
chemical_list: D009573:Nitrites; D033903:Periplasmic Proteins; D050901:Nitrate Reductase