Table 1.
Crystallographic Analysis
| MAD Data Statistics for Seleno-Met | ||||
|---|---|---|---|---|
| λ4 (Low Energy) | λ3 (Inflection) | λ2(Peak) | λ1(Remote) | |
| Space group | P32 | |||
| Cell Parameters | a = b = 105.74 Å, c = 90.52 Å | |||
| Wavelength (Å) | 1.06334 | 0.97935 | 0.97914 | 0.95668 |
| Resolution range (Å) | 50.0–1.90 | |||
| Unique reflections (F > 0) | 89,576 | 88,659 | 89,360 | 88,565 |
| Redundancy | 3.1 | 10.48 | 11.6 | 7.8 |
| Completeness (%) | 100 | 100 | 99.9 | 100 |
| Rmergea(%) | 6.1 | 8.5 | 8.1 | 9.5 |
| Phasing powerb(Friedel) | 1.33 (1.48) | − (1.22) | 0.52 (1.43) | 0.95 (1.19) |
| Rcullisc(Friedel) | 0.73 (0.69) | − (0.74) | 0.94 (0.72) | 0.82 (0.78) |
| Mean FOMd | 0.62/0.91 | |||
| Refinement Statistics | ||||
| Crystal | Seleno-Met | Native I | Native II | |
| Space group | P32 | P32 | P21212 | |
| Cell parameters | a = b = 105.74 Å, c = 90.52 Å | a = b = 105.255 Å, c = 90.486 Å | a = 86.68 Å, b = 93.403 Å, c = 58.578 Å | |
| Beamline | APS-14ID | APS-19BM | APS-19BM | |
| Wavelength (Å) | 1.06334 | 1.03300 | 1.03300 | |
| Resolution range (Å) (last shell) | 20–1.85 (1.90–1.85) | 20–1.85 (1.90–1.85) | 20–1.55 (1.59–1.55) | |
| Unique reflections (last shell) | 88,637 (4,088) | 112,768 (8,263) | 65,305 (4,700) | |
| Redundancy | 3.1 | 3.1 | 6.7 | |
| Completeness (%) (last shell) | 97.0 (94.2) | 99.9 (100) | 98.8 (98.2) | |
| Rmergea% (last shell) | 5.9 (55.0) | 5.5 (47.8) | 6.7 (57.2) | |
| R factor, Rfreee(%) (last shell) | 20.6 (50.4), 23.8 (53.0) | 21.1 (26.1), 24.5 (33.5) | 18.9 (22.6), 21.9 (24.8) | |
| Number of residues in refinement | 3 × 312 = 936 amino acids, 540 H2O, 14 SO4, 8 MES | 3 × 312 = 936 amino acids, 492 H2O, 9 SO4, 6 MES | 323 amino acids, 528 H2O, 4 SO4, 4 MES | |
| Rmsd bonds (Å), angles (°) | 0.017, 1.58 | 0.017, 1.82 | 0.017, 1.64 | |
| Average B factor (Å2) | 31.2 | 24.2 | 16.9 | |
a
Rmerge = ΣhklΣi|I(hkl)i − <I(hkl)>|/ΣhklΣi<I(hkl)i> for i measurements of the intensity I of a reflection hkl.
b
Phasing power is root mean square of (|Fh|/E), where |Fh| is the heavy atom structure factor amplitude and E is the residual lack of closure error; resolution range 27.5–2.5 Å.
c
RCullis is the mean residual lack of closure error divided by the mean anomalous difference; resolution range 27.5–2.5 Å.
d
Prior to and after density modification with phase extension to 1.9 Å.
e
R factor = Σ‖F(obs) | − |F(calc)‖/Σ|F(obs)|; Rfree is the same, calculated with 5% of data withheld from refinement.