Structural Organization of Bacterial RNA Polymerase Holoenzyme and the RNA Polymerase-Promoter Open Complex

摘要: We have used systematic fluorescence resonance energy transfer and distance-constrained docking to define the three-dimensional structures of bacterial RNA polymerase holoenzyme polymerase-promoter open complex in solution. The provide a framework for understanding sigma(70)-(RNA core), sigma(70)-DNA, sigma(70)-RNA interactions. positions sigma(70) regions 1.2, 2, 3, 4 are similar complex. In contrast, position region 1.1 differs dramatically holoenzyme, is located within active-center cleft, apparently serving as "molecular mimic" DNA, but, complex, outside active center cleft. approach described here should be applicable analysis other nanometer-scale complexes.