Transcriptional regulation of the nos genes for nitrous oxide reductase in Pseudomonas aeruginosa
Transcriptional regulation of the nos genes for nitrous oxide reductase in Pseudomonas aeruginosa
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DOI：
10.1099/mic.0.25936-0
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发表时间：
2003-01-01
期刊：
影响因子：
2.8
通讯作者：
Igarashi, Y
中科院分区：
文献类型：
--
作者：
Arai, H;Mizutani, M;Igarashi, Y
一氧化二氮（N2O）还原基因nosrzdyl聚集在铜绿假单胞菌的染色体上。对lacZ进行转录融合的启动子分析显示，氧化亚氮还原酶的结构基因nosZ与上游的nosR基因一起转录。nosR基因产物不是nosR启动子活性所必需的。发现了一个与fnr结合基序相似的序列（41）。在nosR主要转录起始点上游5bp处。基序的突变显著降低了启动子活性。DNR是P. aeruginosa中反硝化基因表达所需的fnr相关转录调控因子，也是nosR转录所必需的，表明该基序被DNR识别。亚硝酸盐（NO2-）、一氧化氮（NO）和NO生成试剂可诱导nosR启动子活性，但N2O不能。NO2-还原酶突变体降低了NO2-诱导的nosR启动子活性。这些结果表明NO是nos基因转录的诱导剂分子。
The genes for nitrous oxide (N2O) reduction, nosRZDFYL, are clustered on the chromosome of Pseudomonas aeruginosa. Promoter assays using transcriptional fusions to lacZ revealed that the structural gene for nitrous oxide reductase, nosZ, is transcribed with the upstream nosR gene. The nosR gene product is not required for the activity of the nosR promoter. A sequence similar to the consensus FNR-binding motif was found 41(.)5 bp upstream from the major transcriptional start point of nosR. Mutation of the motif significantly reduced the promoter activity. DNR, an FNR-related transcriptional regulator required for the expression of denitrification genes in P. aeruginosa, is necessary for the transcription of nosR, indicating that the motif is recognized by DNR. Nitrite (NO2-), nitric oxide (NO) and NO-generating reagents induced nosR promoter activity, but N2O did not. The NO2--induced nosR promoter activity was reduced by mutation of the NO2- reductase mutant. These results indicate that NO is the inducer molecule for transcription of the nos genes.