Chromatin structural transitions in Drosophila embryo cell-free extract result in a high conformational flexibility...

DNA within chromatin has considerably more restricted flexibility in comparison with naked DNA. This raises the main question of how the functioning multi-enzyme complexes overcome the nucleosomal level of DNA packaging. We studied the DNA conformational flexibility of reconstituted chromatin in a cell-free system derived from Drosophila embryo extracts. Using this system, we have found evidence for a energy-independent chromatin remodelling process that efficiently destabilizes the nucleosome structure resulting in a high conformational flexibility of nucleosomal DNA. The described chromatin remodelling process may lay on the basis of defined molecular principles governing the molecular heterogeneity of chromatin structures in vivo.