Espinosa-Urgel M, Tormo A
Departamento de Bioquímica y Biología Molecular I, Facultad de Ciencias Químicas, Universidad Complutense, Madrid, Spain.
Nucleic Acids Res. 1993 Aug 11;21(16):3667-70. doi: 10.1093/nar/21.16.3667.
Expression of a number of genes during stationary phase in Escherichia coli is controlled by the alternative sigma factor sigma s (KatF). Promoters recognized by sigma s do not present a well-defined consensus sequence in their -10 and -35 regions. By polyacrylamide gel electrophoresis of DNA fragments performed at different temperatures, and by computer prediction analyses, we have found that sigma s-regulated promoters are located in regions where DNA shows intrinsic curvatures. This feature does not appear in a stationary-phase-induced promoter which is not controlled by sigma s. We propose that DNA bending may help in recognition and/or binding of sigma s to stationary-phase-induced promoters.
大肠杆菌中许多基因在稳定期的表达受替代σ因子σs（KatF）控制。σs识别的启动子在其-10和-35区域没有明确的共有序列。通过在不同温度下对DNA片段进行聚丙烯酰胺凝胶电泳以及计算机预测分析，我们发现σs调控的启动子位于DNA呈现固有曲率的区域。这一特征在不受σs控制的稳定期诱导型启动子中未出现。我们提出，DNA弯曲可能有助于σs识别和/或结合稳定期诱导型启动子。
