Table 1.

Summary of the steady state ATPase parameters for myosin-2 WT and mutant constructs.

constant	Dd myosin-2 (M765-2R construct)
	WT	K265A	K265E	K265Q
k basal (s−1)	0.097 ± 0.004	0.089 ± 0.004	0.175 ± 0.010	0.131 ± 0.011
k cat (s−1)	2.51 ± 0.38	1.18 ± 0.10	0.72 ± 0.12	4.40 ± 0.70
K app (μM)	83 ± 21	60 ± 10	47 ± 17	230 ± 50
k cat/K app (μM−1s−1)*	0.030 ± 0.016	0.020 ± 0.006	0.015 ± 0.013	0.019 ± 0.009
k cat/K app (μM−1s−1)**	0.035 ± 0.009	0.016 ± 0.001	0.010 ± 0.001	0.021 ± 0.001
Activation***	25.9	13.3	4.11	33.6

Experimental conditions: 25 mM HEPES, 25 mM KCl, 5 mM MgCl₂, 1 mM DTT, 1 mM ATP, pH 7.3; T = 25 °C.

*calculated from k _cat and K _app.

**slope of the first four values of actin-activated ATPase measurements.

***calculated as k _cat/k _basal.