Table 1.
Summary of Tdt mutants measured activity
| Mutation (region) | Observed phenotype wild-type (wt), reduced (−), much reduced (−−) or very much reduced (−−−) Tdt activity | Effect of 1 mM Co++ in Re-establishing full (+) or partial (+/−) template independent Tdt-like activity or none (−) | Remarks (The default enzyme concentration is 2 μM) |
|---|---|---|---|
| S383A (Loop1) | − | + | More pronounced effect at 0.5 μM |
| T384A (Loop1) | wt/− | + | |
| F385A (Loop1) | − | + | More pronounced effect at 0.5 μM |
| P391L (Loop1) | wt/− | + | Sequence as in pol μ |
| S392A (Loop1) | wt | + | Sequence as in pol μ |
| D396A (Loop1) | wt/− | + | |
| Δ1384 (Loop1) | − | + | |
| Δ1392 (Loop1) | − | + | |
| Δ2384/392 (Loop1) | −− | + | |
| Δ3384/391/392 (Loop1) | −−−/Pol | + | More pronounced effect at 0.5 μM |
| Deletion/Loop1 | Pol | +/− | Deletion as in pol λ |
| Chimera/Loop1 | Pol | +/− | |
| D399A (extended SD1) | −−−/Pol | + | More pronounced effect at 0.5 μM |
| H400A (extended SD1) | − | + | |
| F401A (extended SD1) | Pol | − | Template-dep sequence specific pol. |
| Q402E (SD1) | −− | + | |
| Q402A (SD1) | wt | + | |
| QKC=>ERS (SD1) | Pol (stuck) | +/− | Sequence as in pol μ |
| K403A (SD1) | Pol (stuck) | +/− | |
| K403R (SD1) | |||
| C404A (SD1) | wt | + | |
| F405A (extended SD1) | Pol (stuck) | +/− | |
| Pol μ (control) | Pol | +/− | Control (pol μ) |
| D473A (SD2) | Pol | +/− | Less pronounced effect at 0.5 μM |
| N474A (SD2) | wt/− | + | |
| H475A (SD2) | −− | +/− | |
| 473DNH475=>ANA (SD2) | −−−/Pol | +/− | Template-dep. if 4 nt added |
| 473DN474=>NS (SD2) | − | + | Sequence as in pol μ |
| ERS+NS (SD1+SD2) | Pol (stuck) | +/− | Sequence as in pol μ |