Table 4.
Data collection and refinement statistics for the NCX_Mj structures obtained from crystals soaked with varying amounts of Na+ and Ca2+.
| [Ca2+] / [Na+] | 10 mM / 2.5 mM PDB 5HXR | 1 mM / 2.5 mM N/A* | 0.1 mM / 2.5 mM N/A* | 10 mM / 10 mM N/A* |
|---|---|---|---|---|
| Data collection | ||||
| Space group | P212121 | |||
| Cell dimensions | ||||
| a, b, c (Å) | 49.70, 72.52, 96.94 | 49.80, 72.26, 95.80 | 49.48, 72.47, 96.30 | 49.88, 72.22, 96.10 |
| α, β, γ (°) | 90, 90, 90 | 90, 90, 90 | 90, 90, 90 | 90, 90, 90 |
| Resolution (Å) | 2.45 (2.49-2.45) | 2.65 (2.70-2.65) | 2.40 (2.44-2.40) | 2.20 (2.24-2.20) |
| Rsym (%) | 11.8 (94.2) | 11.1 (92.1) | 11.2 (91.3) | 10.3 (99.1) |
| I/σI | 24.4 (1.6) | 20.9 (1.6) | 20.4 (1.6) | 22.4 (1.8) |
| CC1/2 | (0.611) | (0.696) | (0.632) | (0.549) |
| Completeness (%) | 99.7 (100.0) | 99.9 (100.0) | 99.2 (100.0) | 99.7 (100.0) |
| Redundancy | 7.8 (7.8) | 7.0 (6.5) | 6.9 (7.0) | 7.1 (7.1) |
| Refinement | ||||
| Resolution (Å) | 50-2.45 | 50-2.65 | 50-2.40 | 50-2.2 |
| No. reflections | 12996 | 10548 | 13736 | 18080 |
| Rwork/Rfree | 0.22/0.26 | 0.22/0.28 | 0.20/0.26 | 0.19/0.24 |
| No. atoms | ||||
| Protein | 2211 | 2225 | 2228 | 2284 |
| Ligand/Ion | 114/3 | 130/3 | 162/3 | 164/4 |
| Water | 16 | 20 | 42 | 57 |
| B-factors | ||||
| Protein | 64.97 | 71.22 | 53.50 | 45.16 |
| Ligand/Ion | 78.98/60.53 | 90.03/72.90 | 70.67/45.53 | 69.09/42.92 |
| Water | 68.57 | 81.02 | 64.12 | 55.45 |
| R.m.s deviations | ||||
| Bond lengths (Å) | 0.002 | 0.004 | 0.002 | 0.004 |
| Bond angles (°) | 0.630 | 1.143 | 0.686 | 0.650 |
Values in parenthesis are for highest resolution shell. 5% of the data was used in the Rfree calculation. ‘Ligand’ atoms are from lipids, PEG400 and acetates.
*
These structures are virtually identical to that resolved with 10 mM Ca2+ and 2.5 mM Na+ (PDB 5HXR), except for the weakened electron-density signal for the divalent ion, and were therefore not deposited in the PDB.