Table 3.
Crystallographic statistics
| RNase ZF-1a | RNase ZF-3e | |
|---|---|---|
| A. Diffraction data | ||
| Space group | P21 | I222 |
| Unit cell parameters | ||
| a (Å) | 33.2 | 43.2 |
| b (Å) | 39.4 | 61.0 |
| c (Å) | 46.1 | 115.2 |
| β (deg) | 98.8 | |
| Resolution range (Å) | 50–1.35 | 50–1.85 |
| No. reflections measured | 188,114 | 189,062 |
| No. unique reflections | 27,012 | 13,420 |
| Rsymmab | 0.043 (0.313) | 0.115 (0.248) |
| I/σ(I) | 22.8 (2.0) | 14.5 (5.1) |
| Completeness (%) | 93.7 (61.8) | 98.8 (90.6) |
| B. Refined model | ||
| Rcrystb | 0.185 | 0.208 |
| Rfreec | 0.226 | 0.260 |
| Deviation from ideality (r.m.s.) | ||
| Bond lengths (Å) | 0.007 | 0.013 |
| Bond angles (deg) | 1.37 | 1.83 |
| No. atoms | ||
| Protein | 1065 | 982 |
| Water | 159 | 85 |
| Chloride | 1 | 2 |
| Mean B-factor (Å2) | ||
| Protein | 10.0 | 28.2 |
| Water | 19.9 | 34.7 |
| Chloride | 45.8 | 27.4 |
Values in parentheses refer to the outermost shell (1.40–1.35Å and 1.92–1.85 Å for RNase ZF-1a and RNase ZF-3e, respectively).
a
Rsymm = ∑h∑i[|Ii(h)–〈I(h)〉|/∑h∑iIi(h)], where Ii is the ith measurement and 〈I(h)〉 is the weighted mean of all measurements of I(h).
b
Rcryst = ∑h|Fo–Fc|/∑hFo, where Fo and Fc are the observed and calculated structure factor amplitudes of reflection h, respectively.
c
Rfree is equal to Rcryst for a randomly selected 5 % subset of reflections not used in the refinement.74