Anaerobic activation of the entire denitrification pathway in Pseudomonas aeruginosa requires Anr, an analog of Fnr.
The Pseudomonas aeruginosa gene anr, which encodes a structural and functional analog of the anaerobic regulator Fnr in Escherichia coli, was mapped to the SpeI fragment R, which is at about 59 min on the genomic map of P. aeruginosa PAO1. Wild-type P. aeruginosa PAO1 grew under anaerobic conditions with nitrate, nitrite, and nitrous oxide as alternative electron acceptors. An anr deletion mutant, PAO6261, was constructed. It was unable to grow with these alternative electron acceptors; however, its ability to denitrify was restored upon the introduction of the wild-type anr gene. In addition, the activities of two enzymes in the denitrification pathway, nitrite reductase and nitric oxide reductase, were not detectable under oxygen-limiting conditions in strain PAO6261 but were restored when complemented with the anr+ gene. These results indicate that the anr gene product plays a key role in anaerobically activating the entire denitrification pathway.
Ye
R W
RW
Department of Microbiology, Michigan State University, East Lansing 48824, USA.
Haas
D
D
Ka
J O
JO
Krishnapillai
V
V
Zimmermann
A
A
Baird
C
C
Tiedje
J M
JM
D000693:Anaerobiosis / Q000502:physiology; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D001483:Base Sequence; D002874:Chromosome Mapping; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D017353:Gene Deletion; D007506:Iron-Sulfur Proteins; D008969:Molecular Sequence Data; D009589:Nitrogen Oxides / Q000378:metabolism*; D011550:Pseudomonas aeruginosa / Q000235:genetics / Q000378:metabolism*; D015534:Trans-Activators; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000502:physiology*
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C060704:FNR protein, E coli; D007506:Iron-Sulfur Proteins; D009589:Nitrogen Oxides; D015534:Trans-Activators; D014157:Transcription Factors; C072908:ANR protein, Pseudomonas aeruginosa