Yen K M, Gunsalus I C
J Bacteriol. 1985 Jun;162(3):1008-13. doi: 10.1128/jb.162.3.1008-1013.1985.
Tn5 insertion mutations defining a regulatory gene, nahR, of the naphthalene catabolic pathway encoded by the NAH7 plasmid were mapped within a small NAH7 region only a few hundred bases upstream of the nahG gene, the most promoter-proximal gene of the nahGHIJK operon. The nahR mutations blocked the induction of both the nahABCDEF and nahGHIJK operons, and the defect was completely corrected in the presence of the wild-type allele in a trans position. The pleiotropic, recessive, and negative nature of these mutations indicates that the nahR gene specifies a regulatory element which is required to activate both nah operons.
Tn5插入突变确定了由NAH7质粒编码的萘分解代谢途径的一个调控基因nahR，该突变被定位在nahG基因上游仅几百个碱基的一个小的NAH7区域内，nahG基因是nahGHIJK操纵子中最靠近启动子的基因。nahR突变阻断了nahABCDEF和nahGHIJK操纵子的诱导，并且在反式位置存在野生型等位基因的情况下，该缺陷被完全纠正。这些突变的多效性、隐性和负性表明nahR基因指定了一个激活两个nah操纵子所需的调控元件。
