Abstract
We have solved the crystal structures of the yeast chromatin remodeling factor ISW1a (ΔATPase) complex with and without bound duplex DNA at resolutions of 3.60 and 3.25 Å, respectively. The DNA-bound form reveals the characteristic feature of each protein component of ISW1a (HSS and Ioc3) individually gripping a DNA molecule. In addition to these X-ray structures, we have performed Cryo-EM analyses of ISW1a-nucleosome complex, and a biochemical analysis of the remodeling action of ISW1a using a di-nucleosome as substrate. Based on the composite analysis we can elucidate the remodeling mechanism of ISW1a for two nucleosomes in atomic detail.
