Gilman M Z, Glenn J S, Singer V L, Chamberlin M J
Gene. 1984 Dec;32(1-2):11-20. doi: 10.1016/0378-1119(84)90027-1.
Sigma-28-RNA polymerase is a minor form of RNA polymerase found in vegetative cells of Bacillus subtilis which utilizes promoter sites distinct from those recognized by the major RNA polymerase. We have isolated a collection of cloned B. subtilis DNA segments that contain in vitro promoter sites for sigma 28-RNA polymerase by screening a bacteriophage lambda library of B. subtilis genomic fragments. At least nine new sigma 28-specific promoter sites have been identified in this collection, and four have been partially mapped for further study. Our strategy employed a mix of RNA probes prepared by in vitro transcription with sigma 28-RNA polymerase of total B. subtilis DNA EcoRI and HindIII fragments. Over 70% of the unique clones identified contain sigma 28-specific promoter sites, suggesting that the method may have general application for identification of promoter-containing sequences. The efficiency with which sigma 28-specific promoters are detected is consistent with there being a relatively small number of such sites in the B. subtilis genome of which twelve have been cloned.
σ-28-RNA聚合酶是在枯草芽孢杆菌营养细胞中发现的一种次要形式的RNA聚合酶，它利用与主要RNA聚合酶所识别的启动子位点不同的启动子位点。我们通过筛选枯草芽孢杆菌基因组片段的λ噬菌体文库，分离出了一组克隆的枯草芽孢杆菌DNA片段，这些片段含有σ-28-RNA聚合酶的体外启动子位点。在这组片段中至少鉴定出了九个新的σ-28特异性启动子位点，其中四个已进行了部分定位以便进一步研究。我们的策略是使用由枯草芽孢杆菌总DNA的EcoRI和HindIII片段与σ-28-RNA聚合酶进行体外转录制备的RNA探针混合物。所鉴定出的超过70%的独特克隆含有σ-28特异性启动子位点，这表明该方法可能在鉴定含启动子序列方面具有普遍应用价值。检测到σ-28特异性启动子的效率与枯草芽孢杆菌基因组中此类位点数量相对较少一致，其中十二个已被克隆。
