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. 2017 Jan 30;114(7):E1081–E1090. doi: 10.1073/pnas.1616525114

Fig. S4.

Fig. S4.

Photobleaching has a negligible effect on observed Cy3B-GreB dwell times. Reciprocal dwell times (±SE) of Cy3B-GreB(D41N) from EC−6 complexes in the absence of NTPs were measured at three different 532-nm laser excitation powers (blue). Cy3B-GreB(D41N) has longer initial dwell times than Cy3B-GreB in all ECs studied and therefore is a more stringent test of photobleaching. The weighted linear fit (red line) yields a power-specific photobleaching rate of 0.11 ± 0.10 mW−1 s−1. At the excitation powers used in the experiments to examine Cy3B-GreB dwell times (0.7 mW in Fig. 2E and 1.2 mW in Fig. 4F), the reciprocal dwell times (brown) are 0.08 ± 0.07 and 0.13 ± 0.13 s−1, corresponding to 3.2 ± 2.8% and 3.7 ± 3.7%, respectively, of the koff = 1/τ values calculated from the uncorrected dwell times reported in Table 1. The negligible photobleaching supports the use of GreB-absent intervals (29) to measure the association rate constants in Fig. 4 D and E.