Regulation of nitrogen fixation in Azospirillum brasilense.
Regulation of nitrogen fixation in Azospirillum brasilense.
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DOI：
10.1111/j.1574-6968.1997.tb10428.x
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发表时间：
1997-07
影响因子：
2.1
通讯作者：
Yaoping Zhang;R. Burris;P. Ludden;G. Roberts
中科院分区：
文献类型：
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作者：
Yaoping Zhang;R. Burris;P. Ludden;G. Roberts
巴西固氮菌的固氮调控非常复杂，它对外源固定氮或氧浓度的变化有反应。这种调节发生在转录和翻译后水平。与在肺炎克雷伯氏菌中观察到的调控不同，nifA的转录不需要A中的NTRB/NTRC。brasilense中，nifHDK的表达受NIFA活性的翻译后调节控制。外加NH 4+或从微氧条件向厌氧条件的转变也会导致固氮酶活性的迅速丧失。巴西语。这种固氮酶活性的翻译后调节涉及DRAT/DRAG调节系统，这与红杜鹃的调节系统相似。DRAT和DRAG活性都在体内受到调节，但其调节机制尚不清楚。
The regulation of nitrogen fixation in Azospirillum brasilense is very complicated, and it responds to exogenous fixed nitrogen or a change of oxygen concentration. This regulation occurs at both transcriptional and posttranslational levels. Unlike regulation seen in Klebsiella pneumoniae, transcription of nifA does not require NTRB/NTRC in A. brasilense and the expression of nifHDK is controlled by posttranslational regulation of NIFA activity. Addition of NH4+ or a shift from microaerobic to anaerobic conditions also causes a rapid loss of nitrogenase activity in A. brasilense. This posttranslational regulation of nitrogenase activity involves the DRAT/DRAG regulatory system, which is similar to that of Rhodospirillum rubrum. Both DRAT and DRAG activities are regulated in vivo, but the mechanisms for their regulation are unknown.