Table 3. Summary of further crystal-optimization assays for DENV 3 RdRp crystals.
See text for a discussion of crystal-growth optimization. The crystals obtained are shown in Fig. 3 ▶.
| Crystal optimization† | Observation |
|---|---|
| Condition No. 31 (original precipitating solution) | Outcome I |
| Cosmotropic screen (Jeruzalmi & Steitz, 1997 ▶) | |
| Ethylene glycol | |
| 5% | Precipitation |
| 10% | Outcome I |
| 15% | Deters crystal growth |
| Sucrose | |
| 5, 10, 15% | Outcome IV |
| Glycerol | |
| 5, 10% | Outcome IV |
| 15% | Deters crystal growth |
| 2-Propanol | |
| 5, 10% | Deters crystal growth |
| 15% | Precipitation |
| Glucose | |
| 5, 10% | Outcome IV |
| 15% | Outcome I |
| Sparse-matrix cofactor screen (divalent ions; Boddupalli et al., 1992 ▶; Doudna et al., 1993 ▶) | |
| 5 mM CaCl2, 2 mM MgCl2 | Outcome IV |
| 0.2 M MgCl2, 2 mM MgCl2 or 2 mM MnCl2 | Deters crystal growth |
| 5 mM MgCl2, 2 mM MnCl2 or 2 mM MnCl2, 2 mM MgCl2 | Deters crystal growth |
| 5 mM MgSO4, 40 mM MgSO4, 0.2 M MgSO4 or 0.2 M magnesium acetate | Outcome II (optimal conditions) |
| PEG substitution in mother reservoir (crystallization drop using condition No. 31) | |
| PEG 1.5K and 2K [1–2.5%(w/v)] | Outcome III |
| PEG 200 and 400 [2.5–5%(w/v)] | Outcome II (crystal formation after >10 weeks) |
†
Crystal optimization was conducted with condition No. 31 as a starting basis, supplemented with the reagents listed above.