Table 1.
Construct | Ca-ATPase activity, s−1 |
|
Unphosphorylated | Phosphorylated | |
WT | 4.1 | 3.9 |
ΔNHT | 3.1 | 3.4 |
HMM | 3.4 | 3.9 |
S1 | 3.5 | 3.1 |
S639A | 3.4 | 4.1 |
S639D | 3.8 | 3.6 |
4S/E | 3.6 | 3.4 |
Activity was determined in the absence of Mg2+ and F-actin as described in Materials and Methods.