Table II.
Data collection and refinement statistics for the mutant enzymes. All crystals belong to space group C2221 with approximate unit cell dimensions of a = 52.6, b = 150.2, and c = 78.9 Å
| GTA/D302C | GTB/D302A | GTB/D302C | GTB/D302L | GTB/R188K | |
|---|---|---|---|---|---|
| Resolution (Å) | 20–1.54 | 20–1.45 | 20–2.18 | 20–1.69 | 20–1.45 |
| Rsym (%)a,b | 3.8 (32.0) | 2.9 (30.3) | 8.8 (29.4) | 4.6 (32.0) | 3.1 (28.3) |
| Completeness (%)b | 98.7 (100.0) | 99.5 (100.0) | 95.3 (98.8) | 98.3 (100.0) | 96.6 (96.2) |
| Unique reflections | 46,171 | 55,649 | 17,135 | 34,748 | 53,903 |
| Multiplicity | 4.44 | 4.28 | 4.68 | 4.71 | 3.84 |
| <I/σ(I)> | 17.2 | 21.1 | 9.1 | 15.1 | 21 |
| Refinement | |||||
| Reflections used in refinement | 43,837 | 52,822 | 16,261 | 32,996 | 51,167 |
| Rfree reflections | 2329 | 2825 | 874 | 1749 | 2733 |
| Wilson B-factor (Å2) | 20.4 | 21.7 | 32.1 | 22.1 | 20.4 |
| Rwork (%)c | 19.5 | 18.6 | 20.1 | 18.4 | 18.9 |
| Rfree (%)c,d | 21.9 | 20.2 | 24.6 | 22.2 | 20.5 |
| No. non-hydrogen protein atoms | 2247 | 2154 | 2139 | 2229 | 2269 |
| No. water molecules | 270 | 266 | 122 | 229 | 218 |
| r.m.s. angle (°)e | 1.41 | 1.43 | 1.33 | 1.44 | 1.47 |
| r.m.s. bond (Å)e | 0.0092 | 0.0093 | 0.0078 | 0.0093 | 0.0098 |
| Ramachandran outliers (%) | 0 | 0 | 0 | 0 | 0 |
| Protein Data Bank code | 6BJI | 6BJJ | 6BJK | 6BJL | 6BJM |
aRsym = ∑hkl∑i|Ihkl, i – [Ihkl]|/∑hkl ∑iIhkl, i, where [Ihkl] is the average of Friedel-related observations (i) of a unique reflection (hkl).
bValues in parentheses represent highest resolution shell.
cRwork, Σ ||Fo| − |Fc||/Σ |Fo|.
d5% of reflections were omitted for Rfree calculations.
er.m.s., root-mean-square.