Collins J J, Brill W J
J Bacteriol. 1985 Jun;162(3):1186-90. doi: 10.1128/jb.162.3.1186-1190.1985.
Four probes, each specific for a single nif transcript, were used for an analysis of the regulation of nif mRNA synthesis. Transcription of the nifLA operon was repressed by NH4+ but not by amino acids, O2, or temperatures above 37 degrees C. The nifA gene product was required for the activation of transcription of the other nif operons but not nifLA. Synthesis of the other nif transcripts was rapidly turned off by the addition of O2, NH4+, serine, or glutamine. These regulatory effects required the nifL product. However, the nifL product was not required for the cessation of synthesis of these transcripts at elevated temperatures.
使用了四个分别对单个固氮酶转录本具有特异性的探针来分析固氮酶mRNA合成的调控。固氮酶LA操纵子的转录受到NH4+的抑制，但不受氨基酸、O2或37摄氏度以上温度的抑制。固氮酶A基因产物是激活其他固氮酶操纵子转录所必需的，但不是激活固氮酶LA操纵子所必需的。添加O2、NH4+、丝氨酸或谷氨酰胺后，其他固氮酶转录本的合成迅速停止。这些调控作用需要固氮酶L产物。然而，在高温下这些转录本合成的停止并不需要固氮酶L产物。
