Table 1.
Statistics of diffraction data and structure refinement
| Native (form A) | Native (form B) | Hg (OAc)2 Derivative (form B) | K2Pt(CN)4 Derivative (form B) | |
| Diffraction data statistics | ||||
| Space group | C2 | P21212 | P21212 | P21212 |
| Unit cell parameters | ||||
| a (Å) | 98.28 | 224.86 | 224.16 | 224.35 |
| b (Å) | 118.27 | 88.16 | 88.03 | 88.10 |
| c (Å) | 52.59 | 53.95 | 53.87 | 53.88 |
| β (°) | 102.67 | |||
| No. of monomers/asymmetric unit | 2 | 4 | 4 | 4 |
| Resolution (Å) | 1.86 | 2.40a | 2.30 | 2.80 |
| No. of unique reflections | 48,426 | 42,746 | 46,959 | 25,931 |
| Rmerge (%)b | 4.7 (38.3)c | 19.4 (25.5)a | 10.9 (23.8)c | 11.9 (22.6)c |
| Completeness (%) | 99.3 (93.9)c | 99.0 (99.9)a | 96.9 (83.7)c | 95.9 (99.1)c |
| 〈I/σ(I) 〉 | 6.9 (1.3)c | 2.0 (1.9)a | 5.4 (2.1)c | 5.6 (2.9)c |
| ΔFiso (%)d | 14.9 | 9.1 | ||
| ΔFano (%)e | 4.3 | 3.4 | ||
| Refinement statistics | ||||
| No. of amino acid residues | 436 | |||
| No. of GSF | 2 | |||
| No. of solvent molecules | 179 | |||
| R factor (%)f | 17.9 | |||
| Free R factor (%) | 20.3 | |||
| Rms deviation | ||||
| Bond length (Å) | 0.005 | |||
| Bond angles (°) | 1.1 | |||
| Mean temperature factors (Å2) | ||||
| Main-chain atoms | 35 | |||
| Side-chain atoms | 39 | |||
| GSF | 25 | |||
| Solvent | 44 | |||
| Luzzati atomic positional error (Å) | 0.2 | |||
a For native crystal form B, X-ray data were collected to 2.4 Å resolution, but the data in the resolution range higher than 3.0 Å were not used. The numbers in parentheses correspond to the data in the resolution shell 3.02–3.25 Å.
bRmerge = ∑hkl ∑i| Ii (hkl ) − 〈 I(hkl ) 〉|/∑hkl ∑iIi(hkl), where Ii (hkl) is the intensity of the ith observation of reflection hkl and 〈I(hkl)〉 is the mean intensity for reflection hkl from multiple measurements.
c The numbers in parentheses correspond to the data in the highest resolution shell (1.86–1.93 Å , 2.30–2.38 Å , and 2.80–2.90 Å for native crystal from A, Hg derivative, and Pt derivative, respectively). For native crystal form A, the data in the shell (1.86–1.93 Å ) were not used for refinement, and 〈I/σ(I) 〉 in the shell (1.93–2.01 Å ) is 1.8.
d Isomorphous difference ratios between the heavy-atom derivatives (Fph) and the native (Fp) were calculated at 3 Å resolution. ΔFiso = 〈|| Fph |−|Fp|| 〉/〈 (|Fph | + |Fp|)/2〉
e Anomalous difference ratios of the heavy-atom derivatives were calculated at 3 Å resolution. ΔFano= 〈||Fph(+)| − | Fph (−)||〉 /〈(|Fph (+) |(+) |Fph (−) |)/2〉.
fR factor= ∑||Fo| − |Fc ||/∑|Fo|.