Table 3.
Summary of Statistics for Data Collection and Refinement for Caspase-3 and Loop Bundle Mutants
| wild type | E167A | E173A | Y203F | |
|---|---|---|---|---|
| temperature (K) | 100 | 100 | 100 | 100 |
| resolution (Å) | 35.0–1.4 | 35–1.5 | 35–1.3 | 35–2.0 |
| space group | I222 | I222 | I222 | I222 |
| unit cell | ||||
| a (Å) | 68.73 | 67.33 | 68.80 | 67.38 |
| b (Å) | 84.40 | 83.93 | 84.23 | 83.30 |
| c (Å) | 96.35 | 95.50 | 96.14 | 95.92 |
| α, β, γ (deg) | 90 | 90 | 90 | 90 |
| no. of reflections | 54279 | 49333 | 66657 | 58178 |
| completeness (%) | 97.9 (83.8)d | 76.0 (92.9)d | 98.5 (88.3)d | 86.9 (37.2)d |
| I/σ | 46.23 (1.34)d | 34.6 (2.52)d | 50.7 (2.04)d | 45.5 (1.7)d |
| Rmerge (%)a | 5.9 | 9.3 | 11.5 | 14.7 |
| redundancy | 5.8 (3.5)d | 5.1 (2.5)d | 6.5 (3.4)d | 6.5 (6.9)d |
| Rwork (%)b | 19.6 | 20.0 | 19.4 | 17.6 |
| Rfree (%)c | 20.7 | 21.6 | 20.2 | 20.5 |
| rmsd for bond lengths (Å) | 0.005 | 0.005 | 0.005 | 0.006 |
| rmsd for bond angles (deg) | 1.30 | 1.26 | 1.28 | 1.26 |
| rmsd for dihedral angles (deg) | 24.39 | 24.26 | 24.37 | 24.07 |
| rmsd for improper angles (deg) | 1.08 | 1.00 | 1.06 | 0.98 |
| average B factor (Å 2) | 24.84 | 23.8 | 19.71 | 21.83 |
| no. of protein atoms | 1974 | 1935 | 1935 | 1894 |
| no. of water molecules | 290 | 204 | 305 | 251 |
| rmsd | 0.40e | 0.19f | 0.09f | 0.18f |
a
Rmerge = ΣhΣi|I(h,i) − I(h)|/ΣhΣiI(h,i), where I(h,i) values are symmetry-related intensities and I(h) is the mean intensity of the reflection with unique index h.
b
Rwork = Σ ||Fobs| − |Fcalc||/Σ |Fobs|, where Fobs and Fcalc are observed and calculated structure factors, respectively.
c
Rfree = ΣT||Fobs| − |Fcalc||/ΣT|Fobs|, where T is a test data set of 10% of the total reflections randomly chosen and set aside prior to refinement.
d
Data for the highest-resolution shell in parentheses.
e
Compared to the 1CP3 structure as described in the text.
f
Compared to our wild-type caspase-3 structure.