Fisher S H, Rosenkrantz M S, Sonenshein A L
Gene. 1984 Dec;32(3):427-38. doi: 10.1016/0378-1119(84)90018-0.
The glutamine synthetase gene (glnA) of Bacillus subtilis was purified from a library of B. subtilis DNA cloned in phage lambda. By mapping the locations of previously identified mutations in the glnA locus it was possible to correlate the genetic and physical maps. Mutations known to affect expression of the glnA gene and other genes were mapped within the coding region for glutamine synthetase, as determined by measuring the sizes of truncated, immunologically cross-reacting polypeptides coded for by various sub-cloned regions of the glnA gene. When the entire B. subtilis glnA gene was present on a plasmid it was capable of directing synthesis in Escherichia coli of B. subtilis glutamine synthetase as judged by enzymatic activity, antigenicity, and ability to allow growth of a glutamine auxotroph. By use of the cloned B. subtilis glnA gene as a hybridization probe, it was shown that the known variability of glutamine synthetase specific activity during growth in various nitrogen sources is fully accounted for by changes in glnA mRNA levels.
枯草芽孢杆菌的谷氨酰胺合成酶基因（glnA）是从克隆于λ噬菌体的枯草芽孢杆菌DNA文库中纯化得到的。通过绘制glnA基因座中先前鉴定的突变位点，有可能将遗传图谱和物理图谱关联起来。通过测量由glnA基因的各个亚克隆区域编码的截短的、免疫交叉反应性多肽的大小来确定，已知影响glnA基因和其他基因表达的突变被定位在谷氨酰胺合成酶的编码区域内。当整个枯草芽孢杆菌glnA基因存在于质粒上时，根据酶活性、抗原性以及使谷氨酰胺营养缺陷型生长的能力判断，它能够指导大肠杆菌中枯草芽孢杆菌谷氨酰胺合成酶的合成。通过使用克隆的枯草芽孢杆菌glnA基因作为杂交探针，结果表明，在不同氮源中生长期间谷氨酰胺合成酶比活性的已知变异性完全由glnA mRNA水平的变化所解释。
