PHYSICAL JOURNAL E The nucleosome: A transparent, slippery, sticky and yet stable DNA-protein complex

Abstract. Roughly three quarters of eucaryotic DNA are tightly wrapped onto protein cylinders organized in so-called nucleosomes. Despite this fact, the wrapped DNA cannot be inert since DNA is at the heart of many crucial life processes. We focus here on physical mechanisms that might allow nucleosomes to perform a great deal of such processes, speci¯cally 1) on unwrapping °uctuations that give DNA-binding proteins access to the wrapped DNA portions without disrupting the nucleosome as a whole, 2) on corkscrew sliding along DNA and some implications and on 3) tail-bridging{induced attraction between nucleosomes as a means of controlling higher-order folding. PACS. 87.16.Sr Chromosomes, histones { 87.15.He Dynamics and conformational changes