Asymmetric nucleosome PARylation at DNA breaks mediates directional nucleosome sliding by ALC1

Single-molecule Förster resonance energy transfer (FRET) data supporting the findings of the paper titled "Asymmetric nucleosome PARylation at DNA breaks mediates directional nucleosome sliding by ALC1" in Nature Communications. The data mainly pertain to the remodeling directionality of ALC1 as a function of the PARylation state of a nucleosome. The initial remodeling directionality was measured based on the direction of the initial FRET change upon remodeling. The biotinylated FRET-labeled nucleosomes were immobilized on a PEG (poly[ethylene glycol])-coated quartz slide saturated with streptavidin. Cy3 and Cy5 fluorophores were excited with 532 nm Nd:YAG and 638 nm diode lasers, respectively, and fluorescence emissions from Cy3 and Cy5 fluorophores were detected using a custom-built prism-based TIRF microscope. To check the presence of an intact donor fluorophore, the sample was alternately excited with 532 nm and 638 nm lasers during the experiment.