COVALENT MODIFICATION OF THE GLNG PRODUCT, NRI, BY THE GLNL PRODUCT, NRII, REGULATES THE TRANSCRIPTION OF THE GLNALG OPERON IN ESCHERICHIA-COLI
COVALENT MODIFICATION OF THE GLNG PRODUCT, NRI, BY THE GLNL PRODUCT, NRII, REGULATES THE TRANSCRIPTION OF THE GLNALG OPERON IN ESCHERICHIA-COLI
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DOI：
10.1073/pnas.83.16.5909
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发表时间：
1986-08-01
影响因子：
11.1
通讯作者：
MAGASANIK, B
中科院分区：
文献类型：
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作者：
NINFA, AJ;MAGASANIK, B
氮调控启动子（如glnAp2）的转录需要glnG基因产物NRI和rpoN（glnF）基因产物sigma。60，受glnL基因产物NRII调控。我们发现在含有NRI， NRII和ATP的反应混合物中，NRII催化。ATP的磷酸到NRI。NRI的这种共价修饰与反应混合物获得从glnAp2激活转录的能力同时发生。在glnB的产物PII存在的情况下，NRII催化NRI-phosphate脱除磷酸。与此同时，反应混合物也失去了激活glnAp2转录的能力。基于这一证据，我们提出nri -磷酸盐激活氮调控启动子的转录，NRII的作用是控制nri -磷酸盐的形成和分解，以响应细胞氮可用性信号。
Transcription from nitrogen-regulated promoters, such as glnAp2, requires the glnG gene product, NRI, as well as the rpoN(glnF) gene product, .sigma.60, and is regulated by the glnL gene product, NRII. We find that in a reaction mixture containing NRI, NRII, and ATP, NRII catalyzes the transfer of the .gamma. phosphate of ATP to NRI. This covalent modification of NRI occurs concurrently with the acquisition of the ability by the reaction mixture to activate transcription from glnAp2. In the presence of PII, the product of glnB, NRII catalyzes the removal of the phosphate from NRI-phosphate. This reaction occurs concurrently with the loss by the reaction mixture of the ability to activate transcription from glnAp2. On the basis of this evidence, we propose that NRI-phosphate activates transcription from nitrogen-regulated promoters and that the role of NRII is control of the formation and breakdown of NRI-phosphate in response to cellular signals of nitrogen availability.