Meijer Wilfried J J, Salas Margarita
Instituto de Biología Molecular 'Eladio Viñuela' (CSIC), Centro de Biología Molecular 'Severo Ochoa' (CSIC-UAM), Universidad Autónoma, Canto Blanco, 28049 Madrid, Spain.
Nucleic Acids Res. 2004 Feb 18;32(3):1166-76. doi: 10.1093/nar/gkh290. Print 2004.
Various Escherichia coli promoters contain, in addition to the classical -35 and -10 hexamers, a third recognition element, named the UP element. Located upstream of the -35 box, UP elements stimulate promoter activity by forming a docking site for the C-terminal domain of the RNA polymerase alpha subunit (alphaCTD). Accumulating genetic, biochemical and structural information has provided a detailed picture on the molecular mechanism underlying UP element-dependent promoter stimulation in E.coli. However, far less is known about functional UP elements of Bacillus subtilis promoters. Here we analyse the strong early sigma(A)-RNA polymerase-dependent promoters C2, A2c and A2b of the lytic B.subtilis phage phi29. We demonstrate that the phage promoters contain functional UP elements although their contribution to promoter strength is very different. Moreover, we show that the UP element of the A2b promoter, being critical for its activity, is located further upstream of the -35 box than most E.coli UP elements. The importance of the UP elements for the phage promoters and how they relate to other UP elements are discussed.
除了经典的-35和-10六聚体之外，多种大肠杆菌启动子还包含第三个识别元件，称为上游元件（UP元件）。UP元件位于-35框的上游，通过形成RNA聚合酶α亚基C端结构域（αCTD）的对接位点来刺激启动子活性。越来越多的遗传、生化和结构信息为大肠杆菌中UP元件依赖性启动子刺激的分子机制提供了详细的图景。然而，关于枯草芽孢杆菌启动子的功能性UP元件，人们了解得要少得多。在这里，我们分析了裂解性枯草芽孢杆菌噬菌体phi29的强早期σ（A）-RNA聚合酶依赖性启动子C2、A2c和A2b。我们证明，噬菌体启动子含有功能性UP元件，尽管它们对启动子强度的贡献差异很大。此外，我们表明，A2b启动子的UP元件对其活性至关重要，它位于-35框的上游，比大多数大肠杆菌的UP元件更远。文中讨论了UP元件对噬菌体启动子的重要性以及它们与其他UP元件的关系。
