Bradley D, Gatenby A A
EMBO J. 1985 Dec 30;4(13B):3641-8. doi: 10.1002/j.1460-2075.1985.tb04129.x.
This paper describes the use of Escherichia coli to isolate Bal31 deletion mutants and single-base substitution mutants that functionally define the promoter of the maize chloroplast beta-ATPase gene (atpB). Promoter function in E. coli and in a chloroplast in vitro transcription system was determined by S1 nuclease protection experiments using RNA products from each mutant. The results show that in vitro the chloroplast RNA polymerase responds to the promoter point mutations in a quantitatively similar fashion to the E. coli RNA polymerase. Deletion analysis demonstrates that sequences 5' of the -35 region are not necessary for chloroplast promoter function in vitro and that the presence of an adjacent promoter drastically decreases the transcriptional activity of the atpB promoter in E. coli.
本文描述了利用大肠杆菌分离功能上界定玉米叶绿体β -ATP酶基因（atpB）启动子的Bal31缺失突变体和单碱基取代突变体。通过使用来自每个突变体的RNA产物进行S1核酸酶保护实验，确定了该启动子在大肠杆菌和叶绿体体外转录系统中的功能。结果表明，在体外，叶绿体RNA聚合酶对启动子点突变的反应在数量上与大肠杆菌RNA聚合酶相似。缺失分析表明，-35区域5'端的序列对于叶绿体启动子在体外的功能不是必需的，并且相邻启动子的存在会显著降低atpB启动子在大肠杆菌中的转录活性。
