Chen Y M, Backman K, Magasanik B
J Bacteriol. 1982 Apr;150(1):214-20. doi: 10.1128/jb.150.1.214-220.1982.
DNA was prepared from a strain of Escherichia coli bearing a mutation which confers the GlnC phenotype (inability to reduce the expression of glnA and other nitrogen-regulated operons in response to ammonia in the growth medium). A fragment of this DNA carrying glnA, the structural gene for glutamine synthetase, was cloned on plasmid pBR322. By using recombination in vitro, we mapped the GlnC mutation to a region between glnA and glnG. This region defines a gene, glnL, which codes for a trans-acting product; the GlnC mutant produces an altered product. The glnL product plays a key role in the communication of information concerning the quality and abundance of the nitrogen source in the growth medium to a destination responsible for the regulation of glnA and other genes for enzymes responsible for nitrogen utilization.
从携带一种突变的大肠杆菌菌株中制备了DNA，该突变赋予了GlnC表型（无法响应生长培养基中的氨而降低谷氨酰胺合成酶基因（glnA）和其他氮调节操纵子的表达）。携带谷氨酰胺合成酶结构基因glnA的这段DNA片段被克隆到质粒pBR322上。通过体外重组，我们将GlnC突变定位到glnA和glnG之间的一个区域。该区域定义了一个基因glnL，它编码一种反式作用产物；GlnC突变体产生一种改变的产物。glnL产物在将有关生长培养基中氮源的质量和丰度的信息传递到负责调节glnA和其他氮利用酶基因的位点中起关键作用。
