TABLE 2.
Relative activities of the RNase H2A AGS-causing mutants
| RNase H2A | 1-ribo |
4-ribo |
20-ribo |
|||
|---|---|---|---|---|---|---|
| Activitya | Relative activityb | Activitya | Relative activityb | Activitya | Relative activityb | |
| WT | 9.5 ± 1.0 | 1 | 7.8 ± 1.6 | 1 | 8.3 ± 1.6 | 1 |
| G37S | 0.046 ± 0.006 | 1/210 | 2.6 ± 0.4 | 1/3 | 2.5 ± 0.4 | 1/3 |
| R186W | 0.056 ± 0.01 | 1/160 | 0.90 ± 0.2 | 1/9 | 1.0 ± 0.2 | 1/8 |
| R235Q | 0.026 ± 0.004 | 1/370 | 0.013 ± 0.003 | 1/600 | 0.011 ± 0.003 | 1/750 |
| R108W | 3.8 ± 0.3 | 1/3 | 5.3 ± 0.8 | 1/2 | 5.8 ± 0.5 | 1/1 |
| N212I | 10 ± 1 | 1/1 | 7.5 ± 2 | 1/1 | 8.5 ± 0.9 | 1/1 |
| F230L | 0.81 ± 0.1 | 1/12 | 2.3 ± 0.4 | 1/3 | 2.1 ± 0.3 | 1/4 |
| T240M | 1.1 ± 0.2 | 1/9 | 7.2 ± 2 | 1/1 | 16 ± 2 | 2/1 |
| R291H | 21 ± 3 | 2/1 | 17 ± 2 | 2/1 | 18 ± 2 | 2/1 |
a To precisely quantify activities, each enzyme was assayed as described under “Experimental Procedures” in triplicate at four different concentrations that converted less than 30% of substrate to product. Plots of activity versus enzyme concentrations confirmed linearity of the assays and generated the enzyme activity values. The average activities (pmol of product/min/pmol of enzyme) and S.E. for RNase H2 WT and mutants are shown.
b The relative activity was calculated as: relative activity = 1/[(pmol of product/min/pmol of WT enzyme)/(pmol of product/min/pmol of mutant enzyme)].