The narL gene product activates the nitrate reductase operon and represses the fumarate reductase and trimethylamine N-oxide reductase operons in Escherichia coli.
The narL gene product activates the nitrate reductase operon and represses the fumarate reductase and trimethylamine N-oxide reductase operons in Escherichia coli.
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narL 基因产物激活大肠杆菌中的硝酸还原酶操纵子并抑制富马酸还原酶和三甲胺 N-氧化物还原酶操纵子。
DOI：
10.1073/pnas.84.11.3901
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发表时间：
1987
影响因子：
11.1
通讯作者：
Lin,EC
中科院分区：
文献类型：
--
作者：
Iuchi,S;Lin,EC
大肠杆菌可以利用O2、硝酸盐、富马酸盐或三甲胺n -氧化物（Me3NO）作为终端电子受体，并优先利用氧化还原电位最高的电子受体。因此O2阻止了硝酸盐、富马酸盐和Me3NO还原酶的诱导，而硝酸盐则抑制了富马酸盐和Me3NO还原酶的诱导。在厌氧条件下，在硝酸盐的存在下，已知narL基因产物可以激活narC操纵子的转录，narC操纵子编码硝酸盐还原酶。该研究表明，相同的产物在硝酸盐抑制富马酸盐和Me3NO还原酶编码的操作子（frd和tor）中起作用。相反，硝酸对乙醇脱氢酶的厌氧抑制不需要nl产物。narL的表达不需要fnr基因产物，而fnr是narC、frd和tor完全表达所必需的多效激活剂。
Escherichia coli, which can utilize O2, nitrate, fumarate, or trimethylamine N-oxide (Me3NO) as terminal electron acceptor, preferentially utilizes the one with the highest redox potential. Thus O2 prevents induction of nitrate, fumarate, and Me3NO reductases, and nitrate curtails the induction of fumarate and Me3NO reductases. Under anaerobic conditions the narL gene product, in the presence of nitrate, is known to activate transcription of the narC operon, which encodes nitrate reductase. This study shows that the same product plays a role in the repression by nitrate of the operons (frd and tor) that encode fumarate and Me3NO reductases. In contrast, the anaerobic repression of ethanol dehydrogenase by nitrate does not require the narL product. Expression of narL does not require the fnr gene product, a pleiotropic activator that is required for full expression of narC, frd, and tor.