Abstract
Using a transient transfection assay system, we have recently demonstrated that curved DNA that mimics a negative supercoil can activate transcription by influencing chromatin structure. To know whether this phenomenon is general, we investigated the effect of the DNA curvature on transcription in an episomal assay system. It was confirmed that the left-handedly curved DNA can activate transcription even in the episomal system. Furthermore, it was found that conversion of the TATA sequence in the reporter constructs from the original non-canonical sequence to the canonical one considerably elevated transcription from the control template and, as the result, diminished the difference in promoter activity between the control reporter and the reporters containing the left-handedly curved DNA, indicating that transcriptional activation by the DNA curvature is more evident when the TATA box is not optimized.
