The requirement of RpoN (sigma factor sigma54) in denitrification by Pseudomonas stutzeri is indirect and restricted to the reduction of nitrite and nitric oxide.
The rpoN region of Pseudomonas stutzeri was cloned, and an rpoN null mutant was constructed. RpoN was not essential for denitrification in this bacterium but affected the expression levels and enzymatic activities of cytochrome cd1 nitrite reductase and nitric oxide reductase, whereas those of respiratory nitrate reductase and nitrous oxide reductase were comparable to wild-type levels. Since the transcription of the structural genes nirS and norCB, coding for nitrite reductase and the nitric oxide reductase complex, respectively, proceeded unabated, our data indicate a posttranslational process for the two key enzymes of denitrification depending on RpoN.
Lehrstuhl für Mikrobiologie der Universität Karlsruhe, D-76128 Karlsruhe, Germany.
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D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins; D012321:DNA-Directed RNA Polymerases / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation; D050901:Nitrate Reductase; D009565:Nitrate Reductases / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D009572:Nitrite Reductases / Q000235:genetics / Q000378:metabolism*; D009573:Nitrites / Q000378:metabolism*; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D011549:Pseudomonas / Q000235:genetics / Q000378:metabolism*; D051877:RNA Polymerase Sigma 54; D017422:Sequence Analysis, DNA; D012808:Sigma Factor / Q000235:genetics / Q000378:metabolism*
D004268:DNA-Binding Proteins; D009573:Nitrites; D012808:Sigma Factor; D009569:Nitric Oxide; D010088:Oxidoreductases; D009565:Nitrate Reductases; D009572:Nitrite Reductases; C022763:nitrous oxide reductase; C034747:nitric-oxide reductase; D050901:Nitrate Reductase; D012321:DNA-Directed RNA Polymerases; D051877:RNA Polymerase Sigma 54