TABLE 1.
Crystallographic statistics
Values in parentheses are for the high resolution shell.
| ScAGal | ScAGal-melibiose | D149A ScAGal-raffinose | |
|---|---|---|---|
| Crystal data | |||
| Space group | P 4 21 2 | P 4 21 2 | P 21 21 21 |
| Unit cell parameters | |||
| a | 101.24 Å | 100.45 Å | 111.17 Å |
| b | 101.24 Å | 100.45 Å | 129.53 Å |
| c | 111.52 Å | 111.28 Å | 136.78 Å |
| Data collection | |||
| Beamline | ID23.1 (ESRF) | ID14.2 (ESRF) | ID23.1 (ESRF) |
| Temperature | 100 K | 100 K | 100 K |
| Wavelength | 0.979 Å | 0.933 Å | 1.072 Å |
| Resolution | 74.96 to 1.95 Å (2.06 to 1.95 Å) | 59.99 to 2.40 Å (2.53 to 2.40 Å) | 71.80 to 2.70 Å (2.85 to 2.70 Å) |
| Data processing | |||
| Total reflections | 455,518 (73,906) | 238,360 (32,904) | 327,060 (51,340) |
| Unique reflections | 42,919 (6140) | 22,940 (3262) | 54,965 (7932) |
| Multiplicity | 10.6 (12.0) | 10.4 (10.1) | 6 (6.5) |
| Completeness | 100.0% (100.0%) | 99.6% (99.2%) | 100.0% (100.0%) |
| I/σ (I) | 7.6 (1.7) | 6.9 (1.9) | 8.9 (1.8) |
| Mean I/σ (I) | 33.3 (7.1) | 19.4 (5.8) | 19.6 (4.9) |
| Rmergea | 6.7% (45.7%) | 11.1% (43.3%) | 8.1% (43.8%) |
| Rpimb | 2.2% (13.7%) | 3.5% (13.7%) | 3.8% (18.4%) |
| Molecules per ASU | 1 | 1 | 4 |
| Matthews coefficient (Å3 Da−1) | 2.75 | 2.67 | 2.43 |
| Solvent content | 55% | 54% | 49% |
| Refinement | |||
| Rwork/Rfreec (%) | 20.4/23.4% | 19.8/25.3% | 24.1/28.3% |
| No. of atoms | |||
| Protein | 3518 | 3518 | 10,545 |
| Carbohydrate | 130 | 135 | 430 |
| Other | 15 | 1 | 0 |
| Water molecules | 434 | 415 | 1022 |
| Ramachandran (Ref. 21) | |||
| Favored | 97.1% | 96.2% | 96.1% |
| Outliers | 0.00% | 0.00% | 0.00% |
| Root mean square deviations | |||
| Bonds | 0.01 Å | 0.012 Å | 0.008 Å |
| Angles | 1.372° | 1.543° | 1.057° |
| Protein Data Bank codes | 3LRK | 3LRL | 3LRM |
a Rmerge = Σhkl Σi|Ii(hkl) − (I(hkl))|/ΣhklΣi I(hkl), where Ii(hkl) is the ith measurement of reflection hkl, and (I(hkl)) is the weighted mean of all measurements.
b Rpim = Σhkl (1/(N − 1))1/2 Σi|Ii(hkl) − (I(hkl))|/Σhkl Σi Ii(hkl), where N is the multiplicity for the hkl reflection.
c Rwork/Rfree = Σhkl| Fo − Fc|/Σhkl|Fo|, where Fc is the calculated and Fo is the observed structure factor amplitude of reflection hkl for the working/free (5%) set, respectively.