Bozouklian H, Fogher C, Elmerich C
Département des Biotechnologies, Institut Pasteur, Paris.
Ann Inst Pasteur Microbiol (1985). 1986 Jul-Aug;137B(1):3-18. doi: 10.1016/s0769-2609(86)80089-8.
A plasmid which, by complementation, restored a Gln+Nif+ phenotype to the Gln-Nif- Azospirillum brasilense mutant 7029, was isolated from a gene bank of total DNA of A. brasilense Sp7 (ATCC 29145) constructed in the broad host range vector pVK100. This plasmid contained the structural gene (glnA) for glutamine synthetase. The glnA gene was mapped by Tn5 insertion and DNA hybridization with a Klebsiella pneumoniae glnA probe. The direction of transcription of glnA was determined. The glnA product was identified as a 50-Kd polypeptide which could be adenylylated in Escherichia coli, and glutamine synthetase activity was characterized in E. coli. Plasmids containing the glnA gene restored glutamine-independent growth and a Nif+ phenotype to Gln-Nif- and Gln-Nifc mutants of Azospirillum.
通过互补作用使巴西固氮螺菌突变体7029（Gln-Nif-）恢复为Gln+Nif+表型的一个质粒，是从构建于广宿主范围载体pVK100中的巴西固氮螺菌Sp7（ATCC 29145）总DNA基因文库中分离得到的。该质粒含有谷氨酰胺合成酶的结构基因（glnA）。通过Tn5插入以及与肺炎克雷伯菌glnA探针的DNA杂交对glnA基因进行了定位。确定了glnA的转录方向。glnA产物被鉴定为一种50-kD的多肽，其在大肠杆菌中可被腺苷酸化，并对大肠杆菌中的谷氨酰胺合成酶活性进行了表征。含有glnA基因的质粒使巴西固氮螺菌的Gln-Nif-和Gln-Nifc突变体恢复了不依赖谷氨酰胺的生长和Nif+表型。
