Fig. 4: ORC predominantly binds to nucleosomes over bare DNA.
From: Nucleosome-directed replication origin licensing independent of a consensus DNA sequence
a Cartoon of the λARS1 DNA sparsely loaded with Cy3-labeled S.c. nucleosomes (green) and incubated with LD650-labeled ORC (red) and Cdc6. b A representative kymograph showing a λARS1 DNA tether loaded with multiple nucleosomes (positions indicated by green arrowheads), all of which were located at non-ARS1 sites except one. Each nucleosome was observed to be stably bound by ORC (red). The presence of ORC on the nucleosomes is confirmed by turning off the green laser, which showed only the red fluorescence from ORC; alternatively, turning off the red laser showed only the green fluorescence from the nucleosomes. c Fraction of ORC stably bound to nucleosomes (X.l. or S.c.) located at either the ARS1 site or non-ARS1 sites. n indicates the number of ORC molecules analyzed for each condition. d Fraction of nucleosomes (X.l. or S.c.) within a given DNA tether that were observed to be ORC-bound in the presence of 2 nM ORC and 5 nM Cdc6. The number of tethers analyzed for each condition is indicated. Data are presented as mean values ± SD. Significance was obtained using an unpaired two-tailed t-test (ns, p = 0.41). Source data are provided as a Source Data file.
