Table 2.
Effect of Various Mutant D Subunits on Mg-Chelatase Activity upon Mixing after Refolding
| Relative Activity (%) | Amount of D Subunits in Assay (pmol)
|
||
|---|---|---|---|
| D Protein Analyzed | Wild-Type D | Mutant D | |
| Wild type | 362 | 13 | – |
| Wild type | 208 | 6.5 | – |
| Wild type | 100 | 3.2 | – |
| G63E + wild type | 173 | 3.2 | 3.2 |
| D135N + wild type | 168 | 3.2 | 3.2 |
| R194K + wild type | 119 | 3.2 | 3.2 |
| T227L + wild type | 140 | 3.2 | 3.2 |
| D385A + wild type | 119 | 3.2 | 3.2 |
| S387A + wild type | 121 | 3.2 | 3.2 |
| S389A + wild type | 142 | 3.2 | 3.2 |
| L418F + wild type | 115 | 3.2 | 3.2 |
100% activity corresponds to 0.96 pmol Mg-protoporphyrin IX/(min × pmol D subunit) being formed. The amounts of I and H subunits in the assays were both 13 pmol.