Table I. Statistics for data collection, phase determination and refinement.
| Data collection | |||||
|---|---|---|---|---|---|
| p40 |
p70 |
||||
| native | Hg | Pt | native | Hg | |
| Resolution (Å) | 15.0–2.5 | 15.0–2.5 | 15.0–3.0 | 12.0–2.8 | 12.0–3.2 |
| High resolution shell | (2.59–2.50) | (2.59–2.50) | (3.11–3.0) | (2.90–2.80) | (3.31–3.20) |
| No. of crystals | 1 | 2 | 1 | 2 | 1 |
| Unique reflections | 12 537 | 12 656 | 7435 | 21 109 | 14 914 |
| <I/σ(I)> | 35 (7) | 36 (7) | 19 (5) | 25 (6) | 18 (4) |
| Redundancy | 7.2 | 10 | 5.4 | 5.4 | 4.1 |
| Completeness (%) | 97 (79) | 98 (84) | 98 (84) | 96 (96) | 99 (99) |
| Rmerge (%) | 5.4 (16.0) | 4.9 (15.2) | 7.8 (22.9) | 6.6 (34.8) | 7.8 (27.4) |
| Isomorphous differences I (%) |
|
25.1 |
26.3 |
|
15.1 |
| Phasing statisticsa | |||||
| No. of sites | 4 | 5 | 2 | ||
| Phasing power (centrics/acentrics) | |||||
| isomorphous | 1.8/2.4 | 1.3/1.6 | 0.79/0.83 | ||
| anomalous | –/2.3 | –/1.1 | –/0.48 | ||
| Combined figure of merit |
|
0.56/0.56 |
|
0.14/0.19 |
|
| Model refinementb | |||||
| |
|
p40 |
|
p70 |
|
| Resolution range | 15.0–2.5 | 15.0–2.8 | |||
| Refinement data completeness (%) | 95.2 | 95.6 | |||
| Ramachandran plot statistics | |||||
| residues in most favored regions (%) | 88.3 | 78.1 | |||
| residues in additional allowed regions (%) | 10.6 | 16.9 | |||
| residues in generously allowed regions (%) | 0.0 | 3.8 | |||
| residues in disallowed regions (%) | 1.1 | 1.1 | |||
| R-value (%) | 22.7 | 24.1 | |||
| Rfree (%) | 28.1 | 28.4 | |||
| R.m.s.d. (bonds) (Å) | 0.017 | 0.019 | |||
| R.m.s.d. (angles) (°) | 1.88 | 2.2 | |||
| <B-factor> (Å2) protein | 39 | 64 | |||
| R.m.s.d. B-factor main chain bonded atoms (Å2) | 2.2 | 2.2 | |||
aAs reported by SHARP (de La Fortelle and Bricogne, 1997).
bIncludes an anisotropic correction implemented in CNS (Brünger et al., 1998).