TABLE 1.
Crystallographic data collection and refinement statistics
Values in parentheses are for the highest resolution bin. SeMet, selenomethionine; APS, Advanced Photon Source; FOM, figure of merit; r.m.s.d., root mean square deviation.
| Parameter | Native crystal | SeMet |
|---|---|---|
| Space group | P3221 | P3221 |
| a = b (Å) | 76.6 | 80.6 |
| c (Å) | 72.7 | 73.4 |
| X-ray source | APS 24 ID-C | APS 22-BM |
| Wavelength (Å) | 0.97949 | λ1, 0.97625; λ2, 0.97949; λ3, 0.9826 |
| Resolution range (Å) | 50–2.35 | 50–2.5 |
| No. observed reflections | 258,546 | λ1, 96,531; λ2, 108,359; λ3, 95,973 |
| No. unique reflections | 12,891 | λ1, 9876; λ2, 9843; λ3, 9972 |
| Completeness (%) | 95.61 (91) | λ1, 99.9 (100); λ2, 99.9 (100); λ3, 99.9 (100) |
| Redundancy | 6.9 (7.3) | λ1, 5.2 (3.9); λ2, 5.9 (5.9); λ3, 5.9 (3.8) |
| Rmerge | 5.6 (28.0) | λ1, 5.5 (38.9); λ2, 5.3 (77.6); λ3, 4.3 (51.9) |
| FOM (50-2.8 Å) | 0.44 | |
| FOM after density modification (50-2.5 Å)a | 0.86 | |
| I/σ | 22 (3.8) | λ1, 23.5 (1.8); λ2, 23.6 (1.9); λ3, 28.9 (1.4) |
| No. reflections used in refinement (N) | 10,142 | |
| No. reflections used in Rfree | 1011 | |
| No. water molecules | 38 | |
| Protein atoms | 1537 | |
| Rcrystal (%) | 20.7 (29.6) | |
| Rfree (%) | 26.5 (36.9) | |
| Wilson B-factor | 54 | |
| Average B-factor | 67 | |
| r.m.s.d. bond lengths (Å) | 0.008 | |
| r.m.s.d. bond angles | 1.044° | |
| Ramachandran (%) | ||
| Favored | 92.0 | |
| Allowed | 6.8 | |
| Outliers | 1.1 |
a Density modification was performed using Solomon as described under “Experimental Procedures.”