Goodman H J, Woods D R
Department of Microbiology, University of Cape Town, Rondebosch, South Africa.
J Gen Microbiol. 1993 Jul;139(7):1487-93. doi: 10.1099/00221287-139-7-1487.
A Butyrivibrio fibrisolvens glnA gene encoding glutamine synthetase (GS) was cloned on a recombinant plasmid pGS4 which enabled Escherichia coli glnA deletion mutants to utilize (NH4)2SO4 as a sole source of nitrogen. The nucleotide sequence of a 2423 bp DNA segment containing the GS-coding region of B. fibrisolvens was determined and the complete amino acid sequence (701 residues) was deduced. Comparisons of the derived B. fibrisolvens GS protein sequence with the amino acid sequences of GS from other bacteria indicate that it is the second reported example of a type III GS, originally identified in the obligate anaerobe Bacteroides fragilis. The presence of GS in B. fibrisolvens cells and the regulation of the cloned GS in E. coli cells was demonstrated by Western blot analysis.
编码谷氨酰胺合成酶（GS）的溶纤维丁酸弧菌谷氨酰胺合成酶基因（glnA）被克隆到重组质粒pGS4上，该质粒使大肠杆菌谷氨酰胺合成酶缺失突变体能够利用硫酸铵作为唯一氮源。测定了包含溶纤维丁酸弧菌GS编码区的2423 bp DNA片段的核苷酸序列，并推导了完整的氨基酸序列（701个残基）。将推导的溶纤维丁酸弧菌GS蛋白序列与其他细菌的GS氨基酸序列进行比较，结果表明它是III型GS的第二个报道实例，最初在专性厌氧菌脆弱拟杆菌中鉴定到。通过蛋白质免疫印迹分析证明了溶纤维丁酸弧菌细胞中GS的存在以及大肠杆菌细胞中克隆的GS的调控。
