Kinetic control of nucleosome displacement by ISWI/ACF chromatin remodelers

摘要

Chromatin structure is dynamically organized by chromatinremodelers, motor protein complexes which moveand remove nucleosomes. The regulation of remodeleraction has recently been proposed to underlie a kineticproofreading scheme which combines the recognition ofhistone-tail states and the ATP-dependent loosening ofDNA around nucleosomes. Members of the ISWI-familyof remodelers additionally recognize linker lengthbetween nucleosomes. Here, we show that the additionalproofreading step involving linker length alone is sufficientto promote the formation of regular arrays ofnucleosomes. ATP-dependent remodeling by bidirectionalmotors is shown to reinforce positioning as comparedto statistical positioning.