Table 1. Crystal data and refinement statistics.
| apoCpI | CpIADT | CpIPDT | CpIODT | CpISDT | |
| A. Crystallographic data | |||||
| X-ray source | SPring8-BL44XU | SLS-PXII | SLS-PXII | SLS-PXII | SLS-PXII |
| Space group | P21 | P21 | P21 | P21 | P21 |
| Unit-cell parameters | |||||
| a (Å) | 90.06 | 91.34 | 87.47 | 89.66 | 89.83 |
| b (Å) | 71.81 | 73.65 | 72.07 | 72.45 | 73.13 |
| c (Å) | 103.31 | 103.88 | 102.71 | 102.94 | 103.04 |
| Wavelength (Å) | 0.900 | 0.978 | 0.979 | 0.979 | 0.979 |
| Resolution range (Å) | 50.00–1.60 | 48.365–1.63 | 47.58–1.82 | 47.77–1.73 | 48.03–1.93 |
| (1.63–1.60) a | (1.67–1.63) | (1.87–1.82) | (1.77–1.73) | (1.98–1.93) | |
| Total reflections | 645 133 (31 520) | 3 729 315 (129 491) | 760 236 (56 288) | 929 911 (70 575) | 674 928 (47 804) |
| Unique reflections | 172 056 (8519) | 170 277 (12 470) | 112 496 (8270) | 136 702 (10 132) | 99 824 (7353) |
| Completeness (%) | 99.7% (99.5%) | 99.9% (99.7%) | 99.9% (100.0%) | 100.0% (100.0%) | 99.9% (99.9%) |
| R meas (%) | 5.2% (56.5%) | 8.7% (109.1%) | 14.3% (98.8%) | 8.7% (83.1%) | 15.8% (93.6%) |
| I/σ(I) | 36.8 (3.2) | 20.6 (2.2) | 9.6 (2.0) | 14.1 (2.1) | 9.9 (2.1) |
| Correlation coefficient (CC 1/2) b | — (—) | 99.9 (87.1) | 99.7 (77.9) | 99.9 (84.1) | 99.6 (68.8) |
| B. Refinement statistics | |||||
| PDB code | 4XDD | 4XDC | 5BYR | 5BYQ | 5BYS |
| Resolution (Å) | 1.60 | 1.63 | 1.82 | 1.73 | 1.93 |
| R work | 0.14 | 0.15 | 0.16 | 0.15 | 0.16 |
| R free | 0.17 | 0.18 | 0.19 | 0.18 | 0.19 |
| No. atoms (except H) | 10 548 | 10 385 | 9859 | 9978 | 9991 |
| Protein | 9050 | 9047 | 8893 | 8982 | 8903 |
| Ligand | 72 | 106 | 106 | 106 | 106 |
| Solvent/ion | 1426 | 1232 | 860 | 890 | 982 |
| RMSD from ideal | |||||
| Bond lengths (Å) | 0.006 | 0.013 | 0.018 | 0.009 | 0.014 |
| Bond angles (°) | 0.95 | 1.28 | 1.48 | 1.07 | 1.28 |
| Ramachandran plot | |||||
| Most favored (%) | 97.67 | 96.90 | 96.32 | 97.23 | 96.59 |
| Additionally allowed (%) | 2.33 | 3.02 | 3.68 | 2.77 | 3.41 |
| Outliers (%) | 0.00 | 0.09 | 0.00 | 0.00 | 0.00 |
| B factors | |||||
| Overall | 35.0 | 39.0 | 32.0 | 35.0 | 32.0 |
| 2FeH cavity (chain A/chain B) | 19.5/22.7 | 24.5/22.0 | 19.0/16.8 | 22.3/19.3 | 18.6/17.3 |
| 2FeH (chain A/chain B) | —/— | 23.3/20.7 | 19.3/17.6 | 23.1/20.2 | 18.5/17.3 |
| Average occupancy of 2FeH (chain A/chain B) | —/— | 0.98/0.95 | 0.94/0.96 | 0.93/0.96 | 0.98/0.97 |
aNumbers in parenthesis represent values for the highest resolution bin.
bCorrelation coefficient CC (1/2) as defined in Karplus and Diederichs 2012.55