Induction of altered chromatin structures by simian virus 40 enhancer and promoter elements

Two simian virus 40 transcriptional promoter elements, the 72-base pair (bp) repeat and the 21-bp repeat region, induce chromatin structures of increased DNase I sensitivity when transposed elsewhere in the viral genome. The induction of a sufficiently long stretch of DNase I-sensitive chromatin leads to the appearance of a visible nucleosome-free region.