Goodman H J, Woods D R
Department of Microbiology, University of Cape Town, Rondebosch, South Africa.
Gene. 1990 Sep 28;94(1):77-82. doi: 10.1016/0378-1119(90)90470-c.
The nucleotide sequence of a 2.5-kb DNA segment containing the Bacteroides fragilis recA gene was determined. The coding region of the recA gene specifies a protein of 318 amino acids. The RecA protein of B. fragilis shows significant homology with that of Escherichia coli, Thiobacillus ferrooxidans, Pseudomonas aeruginosa and Proteus mirabilis. No SOS box characteristic of LexA-regulated promoters could be identified in the 5'-noncoding region of the B. fragilis recA gene. Promoter activity of the cloned recA gene in E. coli was located within a 113-bp fragment of the B. fragilis DNA by in vitro construction of operon fusions with a promoterless lacZ gene. The transcription start point for this gene in B. fragilis was determined by primer extension analysis.
测定了包含脆弱拟杆菌recA基因的一个2.5kb DNA片段的核苷酸序列。recA基因的编码区编码一个由318个氨基酸组成的蛋白质。脆弱拟杆菌的RecA蛋白与大肠杆菌、氧化亚铁硫杆菌、铜绿假单胞菌和奇异变形杆菌的RecA蛋白具有显著的同源性。在脆弱拟杆菌recA基因的5'非编码区未发现LexA调控启动子特有的SOS框。通过与无启动子的lacZ基因体外构建操纵子融合体，确定了克隆的recA基因在大肠杆菌中的启动子活性位于脆弱拟杆菌DNA的一个113bp片段内。通过引物延伸分析确定了该基因在脆弱拟杆菌中的转录起始点。
