Zhu J B, Yu G Q, Jiang Q Y, Wang L W, Shen S J
Sci Sin B. 1983 Dec;26(12):1258-68.
This paper describes the role of nifA product on the ammonia regulation of nitrogen fixation in K. pneumoniae. A plasmid carrying nifA gene under the promoter of tetracycline resistance gene was constructed. When this nifA carrying plasmid was introduced into a glnAG mutant, the Nif- phenotype of this gln mutant was suppressed. Furthermore, when the plasmid was introduced into the wild type and glnAG mutant, derepression of nitrogenase synthesis in ammonia occurred in both strains and the products of nif genes can be detected by two-dimensional gel electrophoresis in the extracts of these ammonia-grown bacterial cells. The constitutive synthesis of nitrogenase in NH4+ was also demonstrated in free living nitrogen-fixing bacteria, Enterobacter cloacae, when the bacteria received the plasmid carrying nifA gene from K. pneumoniae.
本文描述了肺炎克雷伯氏菌中nifA产物在氨对固氮作用调控中的作用。构建了一个在四环素抗性基因启动子控制下携带nifA基因的质粒。当将这个携带nifA的质粒导入谷氨酰胺合成酶基因（glnAG）突变体时，该谷氨酰胺合成酶突变体的固氮缺陷型（Nif-）表型得到了抑制。此外，当将该质粒导入野生型和谷氨酰胺合成酶基因（glnAG）突变体时，两种菌株在氨存在的情况下均出现了固氮酶合成的去阻遏现象，并且在这些在氨中生长的细菌细胞提取物中，通过二维凝胶电泳可以检测到nif基因的产物。当阴沟肠杆菌这种自生固氮菌从肺炎克雷伯氏菌获得携带nifA基因的质粒时，也证明了在NH4+存在的情况下固氮酶的组成型合成。
