Table 1.
Deaminase activity on C and mC of all APOBEC proteins assayed at the indicated pH with the preferred substrate motifs.
| Enzyme | C deaminase activity (nM prod/μM enz) | mC deaminase activity (nM prod/μM enz) | mC selectivity factor (mC/C) x 100 | pH | Substrate motifs |
|---|---|---|---|---|---|
| AID | 48.8 ± 2.1 | 5.3 ± 0.3 | 10.9 | 7.5 | GCA/GmCA |
| Apo1 | 53.5 ± 2.3 | 5.2 ± 1.7 | 9.7 | 6.5 | TCA/TmCA |
| Apo2 | – | – | – | – | – |
| A3A | 256,000 ± 41,000 | 40,300 ± 4,500 | 15.7 | 6.5 | TCA/TmCA |
| A3B | 1,200 ± 50 | 78.1 ± 6.6 | 6.5 | 5.5 | TCA/TmCA |
| A3C | 1,830 ± 120 | 31.4 ± 3.0 | 1.7 | 5.5 | TCA/TmCA |
| A3D | 53.1 ± 4.5 | ND | – | 6.5 | ACA/AmCA |
| A3F | 59.1 ± 1.7 | 2.6 ± 0.8 | 4.4 | 6.5 | TCA/TmCA |
| A3G | 102 ± 4 | 10.3 ± 0.8 | 9.9 | 6.5 | CCC/CCmC |
| A3H | 34,600 ± 1,700 | 18,300 ± 1,200 | 53.0 | 6.5 | TCA/TmCA |
| Apo4 | – | – | – | – | – |
Note: Deaminase activity for C and mC was calculated from the initial linear range of dose dependent product yield for each APOBEC protein (Fig. 3). S.D. was estimated from three independent deaminase assay experiments. The mC selectivity factor was calculated as mC/C activity x 100. ND indicates not determined.