Regulation of the nitrate reductase operon narKGHJI by the cAMP-dependent regulator GlxR in Corynebacterium glutamicum.
The Corynebacterium glutamicum anaerobic nitrate reductase operon narKGHJI is repressed by a transcriptional regulator, ArnR, under aerobic conditions. A consensus binding site of the cAMP receptor protein (CRP)-type regulator, GlxR, was recently found upstream of the ArnR binding site in the narK promoter region. Here we investigated the involvement of GlxR and cAMP in expression of the narKGHJI operon in vivo. Electrophoretic mobility shift assays showed that the putative GlxR binding motif in the narK promoter region is essential for the cAMP-dependent binding of GlxR. Promoter-reporter assays showed that mutation in the GlxR binding site resulted in significant reduction of narK promoter activity. Furthermore, a deletion mutant of the adenylate cyclase gene cyaB, which is involved in cAMP synthesis, exhibited a decrease in both narK promoter activity and nitrate reductase activity. These results demonstrated that C. glutamicum GlxR positively regulates narKGHJI expression in a cAMP-dependent manner.
Nishimura
Taku
T
Research Institute of Innovative Technology for the Earth (RITE), 9-2 Kizugawadai, Kizugawa, Kyoto, 619-0292, Japan.
Teramoto
Haruhiko
H
Research Institute of Innovative Technology for the Earth (RITE), 9-2 Kizugawadai, Kizugawa, Kyoto, 619-0292, Japan.
Toyoda
Koichi
K
Research Institute of Innovative Technology for the Earth (RITE), 9-2 Kizugawadai, Kizugawa, Kyoto, 619-0292, Japan.
Inui
Masayuki
M
Research Institute of Innovative Technology for the Earth (RITE), 9-2 Kizugawadai, Kizugawa, Kyoto, 619-0292, Japan.
Yukawa
Hideaki
H
Research Institute of Innovative Technology for the Earth (RITE), 9-2 Kizugawadai, Kizugawa, Kyoto, 619-0292, Japan.
D019677:Artificial Gene Fusion; D001426:Bacterial Proteins / Q000378:metabolism*; D048230:Corynebacterium glutamicum / Q000235:genetics / Q000502:physiology*; D000242:Cyclic AMP / Q000378:metabolism*; D004269:DNA, Bacterial / Q000378:metabolism; D024202:Electrophoretic Mobility Shift Assay; D017353:Gene Deletion; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D017930:Genes, Reporter; D050901:Nitrate Reductase / Q000096:biosynthesis* / Q000235:genetics; D009876:Operon; D011401:Promoter Regions, Genetic; D011485:Protein Binding
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D000242:Cyclic AMP; D050901:Nitrate Reductase