title: The assimilatory nitrate reduction system of the phototrophic bacterium Rhodobacter capsulatus E1F1.
abstract: The phototrophic bacterium Rhodobacter capsulatus E1F1 assimilates nitrate under anaerobic phototrophic growth conditions. A 17 kb DNA region encoding the nitrate assimilation (nas) system of this bacterium has been cloned and sequenced. This region includes the genes coding for a putative ABC (ATP-binding cassette)-type nitrate transporter (nasFED) and the structural genes for the enzymes nitrate reductase (nasA), nitrite reductase (nasB) and hydroxylamine reductase (hcp). Three genes code for putative regulatory proteins: a nitrite-sensitive repressor (nsrR), a transcription antiterminator (nasT) and a nitrate sensor (nasS). Other genes probably involved in nitrate assimilation are also present in this region. The sequence analysis of these genes and the biochemical properties of the purified nitrate, nitrite and hydroxylamine reductases are reviewed.
authors.affiliation: Departamento de Bioquímica y Biología Molecular, Edificio Severo Ochoa, Universidad de Córdoba, 14071 Córdoba, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Pino
authors.forename: F
authors.initials: F
authors.lastname: Olmo-Mira
authors.forename: P
authors.initials: P
authors.lastname: Cabello
authors.forename: M
authors.initials: M
authors.lastname: Martínez-Luque
authors.forename: F
authors.initials: F
authors.lastname: Castillo
authors.forename: M D
authors.initials: MD
authors.lastname: Roldán
authors.forename: C
authors.initials: C
authors.lastname: Moreno-Vivián
mesh_terms: D000693:Anaerobiosis; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D050901:Nitrate Reductase / Q000235:genetics / Q000378:metabolism; D009566:Nitrates / Q000378:metabolism*; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism; D016354:Rhodobacter capsulatus / Q000235:genetics / Q000378:metabolism*; D017422:Sequence Analysis, DNA
chemical_list: D001426:Bacterial Proteins; D009566:Nitrates; D021122:Protein Subunits; D010088:Oxidoreductases; C021402:hydroxylamine reductase; D050901:Nitrate Reductase