Inouye S, Nakazawa A, Nakazawa T
J Bacteriol. 1985 Sep;163(3):863-9. doi: 10.1128/jb.163.3.863-869.1985.
The xylR gene is a regulatory gene on the TOL plasmid, which acts in a positive manner on xyl operons for degradation of toluene and xylenes in Pseudomonas putida. A DNA fragment containing the xylR promoter region was cloned on promoter-probing vectors, and its nucleotide sequence was determined. The transcription initiation site of the xylR gene was determined in cells of P. putida and Escherichia coli by S1 nuclease and reverse transcriptase mapping. Two initiation sites were detected which were identical in both P. putida and E. coli. The amounts of mRNA synthesized in both bacterial cells were almost the same and independent of the inducers for xyl operons. The consensus sequences for E. coli promoters were found in the region preceding the respective transcription initiation sites. The product of the xylR gene was identified by the maxicell system as a protein with an approximate molecular weight of 67,000.
木糖R基因是TOL质粒上的一个调控基因，它以正向方式作用于恶臭假单胞菌中用于降解甲苯和二甲苯的木糖操纵子。将包含木糖R启动子区域的DNA片段克隆到启动子探测载体上，并测定其核苷酸序列。通过S1核酸酶和逆转录酶作图在恶臭假单胞菌和大肠杆菌细胞中确定了木糖R基因的转录起始位点。检测到两个起始位点，它们在恶臭假单胞菌和大肠杆菌中是相同的。两种细菌细胞中合成的mRNA量几乎相同，且与木糖操纵子的诱导剂无关。在各个转录起始位点之前的区域发现了大肠杆菌启动子的共有序列。通过大细胞系统鉴定出木糖R基因的产物是一种分子量约为67,000的蛋白质。
