Arditti R, Grodzicker T, Beckwith J
J Bacteriol. 1973 May;114(2):652-5. doi: 10.1128/jb.114.2.652-655.1973.
In Escherichia coli the transcription of the lactose operon, like other catabolite-sensitive operons, requires catabolite gene activator protein and 3',5'-cyclic adenosine monophosphate in addition to ribonucleic acid polymerase. We isolated and analyzed lac(+) revertants from a crp(-) strain of E. coli. We found that revertants with a higher level of expression only for the lac operon lie in the lac promoter region. These promoter mutations have no effect on operator or repressor function. Two of the revertants in which the lesions have been more precisely mapped carry mutations in the operator proximal segment of the promoter.
在大肠杆菌中,乳糖操纵子的转录与其他受分解代谢物敏感的操纵子一样,除了核糖核酸聚合酶外,还需要分解代谢物基因激活蛋白和3',5'-环磷酸腺苷。我们从大肠杆菌的crp(-)菌株中分离并分析了lac(+)回复突变体。我们发现,仅乳糖操纵子表达水平较高的回复突变体位于lac启动子区域。这些启动子突变对操纵基因或阻遏蛋白功能没有影响。其中两个回复突变体的损伤已被更精确地定位,它们在启动子的操纵基因近端区段携带突变。