TABLE 1.
Crystal parameters and refinement statistics
| Crystal parameter or refinement statistic | Valuea |
|---|---|
| Data collection | |
| Space group | P212121 |
| Cell dimensions | |
| a (Å) | 70.1 |
| b (Å) | 73.9 |
| c (Å) | 115.5 |
| Solvent content (%) | 58 |
| Resolution range (Å) | 44.6-2.3 (2.38-2.3) |
| Measured reflections | 109,248 (10,555) |
| Unique reflections | 27,358 (2,678) |
| Completeness (%) | 96.8 (98.4) |
| Rmergeb | 0.140 (0.246) |
| I/σ(I) | 4.6 (2.4) |
| Refinement | |
| Refinement range (Å) | 20-2.3 (2.38-2.3) |
| No. of reflections in refinements | 26,306 (2,560) |
| R factor (%)c | 20.1 (24.5) |
| Rfree factor (%)c | 25.9 (29.4) |
| No. of all nonhydrogen atoms | 3,808 |
| No. of protein nonhydrogen atoms | 3,303 |
| No. of acarbose nonhydrogen atoms | 65 |
| No. of calcium ions | 3 |
| No. of water molecules | 437 |
| Average B factor (Å2) | 21.6 |
| Protein atoms (Å2) | 20.7 |
| Acarbose atoms (Å2) | 23.2 |
| Calcium ions (Å2) | 18.0 |
| Water molecules (Å2) | 28.1 |
| r.m.s. deviations | |
| Bond lengths (Å) | 0.006 |
| Bond angles (°) | 1.2 |
a
Values in parentheses are for the highest-resolution shell.
b
Rmerge = Σ|I − 〈I〉|/ΣI, where I is the observed intensity and 〈I〉 is the average intensity for replicated data.
c
R factor is defined as R = Σ||Fobs| − |Fcalc||/Σ|Fobs|, where Fobs is the observed F and Fcalc is the calculated F. Rfree factor was calculated using 10% of the unique reflections.