Fig. 4: The frequency of SWR1C-induced nucleosome unwrapping increases with the addition of ATP.
From: H2A.Z deposition by SWR1C involves multiple ATP-dependent steps
a Example trajectory highlighting unwrapping events (*) that occur in the priming phase for 0 μM ATP (left side) and 100 μM ATP. The Cy3B donor fluorophore was excited, and donor emission (green) and ATTO 647N acceptor emission (red) were recorded (top panel) and used to calculate energy transfer efficiency (blue, bottom panel). b Priming phase E.T. transition density plot. The intensity of E.T. transitions are normalized to the total observation window, for nucleosome substrate lacking SWR1C and ATP (N = 73 nucleosomes with an initial E.T. state > 0.6 from 4 replicates) (blue), and for nucleosome substrate in the presence of SWR1C with 0 μM ATP (N = 491 nucleosomes with an initial E.T. state > 0.6 from 9 replicates) (magenta) and 100 μM ATP (N = 487 nucleosomes with an initial E.T. state > 0.6 from 8 replicates) (orange). c Model of nucleosome unwrapping events, red ball represents Atto647N, and green ball represents Cy3b fluorescent labels. d Distribution in unwrapping event dwell times for 0 μM ATP (N = 491 nucleosomes with an initial E.T. state > 0.6 from 9 replicates) (magenta) and 100 μM ATP (N = 487 nucleosomes with an initial E.T. state > 0.6 from 8 replicates) (orange) for unpaired two-sided student t-test. Source data for panel (d) is provided with this manuscript.
