Example of ensemble refinement for dataset 1UOY. (A) Optimisation of empirical ensemble refinement parameters (τx, pTLS and Tbath). Simulations are performed independently and in parallel. The plot …
Ensemble refinement parameters and results as function of resolution of the datasets. (A) Gain in Rfree of ensemble refinement compared with re-refinement using phenix.refine, (B) number of …
Validation of ensemble refinement using dataset 1YTT with exceptionally high quality experimental phases. (A) Real space cross-correlation of experimentally phased electron density map (|Fobs|exp[iφo…
Sampling reproducibility of ensemble refinement. (A) Cross-correlations (CC) calculated for all pairs from 10 random-number seed repeat ensemble refinements of the 1UOY dataset extending to 1.5-Å …
Reproducibility of side-chain rotamer distributions. Mean χ1 and χ2 distributions of four side-chains from the 10 repeats, with error bars ±1 σ, are shown for 1UOY. The four residues presented are …
Ramachandran analysis. Distribution of Ramachandran torsion angles classified as outliers (red) and allowed (blue) for ensemble models, 1UOY (A) and 1BV1 (B). Plot shows percentage of classification …
Geometries of single-structure models and ensemble models.
Rms deviations (RMSD) from ideal bond, angle and dihedral geometries calculated for single structures re-refined using phenix.refine. Geometries for ensemble structures were calculated using two methods, the ‘whole distribution’, where the RMSD was calculated for each restraint (averaged over all structures), √〈(xideal − xmodel)2〉, and ‘centroid’ where the RMSD was calculated using the mean deviation from ideality for each restraint, √〈(〈xideal − xmodel〉)2〉, which for unimodal functions equals √〈(xideal − 〈xmodel〉)2〉.
Ramachandran statistics for re-refined and ensemble models.
The Ramachandran statistics for the ensemble models are calculated in two ways: ‘Ramachandran (mean)’ shows the percentage of outliers, allowed and favoured averaged over all structures in the ensemble (cf. ‘whole distribution’ in Figure 6—source data 1), whereas ‘Ramachandran (mode)’ shows these percentages based on the most frequent occurring classification of each φ,ψ combination (cf. ‘centroid distribution’ in Figure 6—source data 1).
Comparison of atomic fluctuations for non-crystallographic symmetry related protein copies for dataset 1M52. (A) Cα trace of the re-refined single structure coloured by B-factor (from blue to red …
Comparison of atomic fluctuations for NCS related protein copies for dataset 2R8Q.
Comparison of atomic fluctuations for NCS related protein copies for dataset 1YTT.
Comparison of atomic fluctuations for NCS related protein copies for dataset 1IEP.
Comparison of atomic fluctuations for NCS related protein copies for dataset 2XFA.
Ensemble refinement of two isomorphous proline isomerase datasets collected at 100 K and 288 K. (A) Left, basal TLS B-factors of ensemble models for 100 K and 288 K datasets (blue and green, …
Overview of side-chain dynamics in ensemble structures. Atoms are coloured by their relative probability in the ensemble (see ‘Materials and methods’), reflecting the degree of disorder (ranging …
Dynamics in the binding pocket of proline isomerase at 288 K. (A) The location of the binding pocket comprised of residues Arg55, Met61, Ser99 and Phe113. (B) Zoom in of binding pocket (as dotted …
Comparison of ensemble structures of bound and unbound forms of HIV protease. (A) Residues in the P1 binding sites are disordered in the unbound HIV protease (2PC0), left-hand side, with carbon …
ABL-kinase Imatinib binding site. (A) Imatinib binding site in chain A of the 1IEP dataset showing distribution of the six protein–ligand hydrogen bonds in chain A and chain B (red and blue …
Correlation of R-values and overall map correlation coefficient for the 1YTT dataset in the block selection procedure. The correlation coefficients are calculated between the experimentally phased …
Interpretation of global and local details of 1UOY ensemble model is aided by relative atomic probability (as described in ‘Materials and methods’). Ensemble models, left and centre, are colour by …
Ensemble refinement statistics for 20 datasets. Datasets were taken from the PDB or PDB_REDO and were re-refined using ensemble refinement and phenix.refine. The relaxation time τx used, the …
PDB ID | Resolution (Å) | Ensemble refinement | phenix.refine | Ensemble—phenix.refine | |||||
τx (ps) | No. of structures | Rwork | Rfree | Rwork | Rfree | ΔRwork | ΔRfree | ||
1KZK | 1.1 | 1.5 | 600 | 0.125 | 0.153 | 0.136 | 0.155 | −0.011 | −0.003 |
3K0M | 1.3 | 2.0 | 250 | 0.104 | 0.129 | 0.116 | 0.132 | −0.012 | −0.003 |
3K0N | 1.4 | 1.0 | 209 | 0.115 | 0.133 | 0.119 | 0.143 | −0.004 | −0.010 |
2PC0 | 1.4 | 0.8 | 250 | 0.145 | 0.188 | 0.161 | 0.193 | −0.016 | −0.005 |
1UOY | 1.5 | 1.0 | 167 | 0.104 | 0.137 | 0.155 | 0.185 | −0.051 | −0.049 |
3CA7 | 1.5 | 0.8 | 40 | 0.149 | 0.184 | 0.171 | 0.212 | −0.022 | −0.029 |
2R8Q | 1.5 | 1.0 | 200 | 0.132 | 0.162 | 0.158 | 0.178 | −0.026 | −0.016 |
3QL0 | 1.6 | 0.5 | 70 | 0.204 | 0.254 | 0.229 | 0.270 | −0.024 | −0.017 |
1X6P | 1.6 | 1.0 | 400 | 0.121 | 0.149 | 0.140 | 0.175 | −0.019 | −0.026 |
1F2F | 1.7 | 0.8 | 143 | 0.128 | 0.168 | 0.160 | 0.198 | −0.032 | −0.031 |
3QL3 | 1.8 | 0.5 | 80 | 0.160 | 0.208 | 0.170 | 0.221 | −0.010 | −0.013 |
1YTT | 1.8 | 0.3 | 84 | 0.139 | 0.174 | 0.166 | 0.189 | −0.027 | −0.014 |
3GWH | 2.0 | 1.0 | 39 | 0.160 | 0.200 | 0.187 | 0.220 | −0.027 | −0.021 |
1BV1 | 2.0 | 0.4 | 78 | 0.149 | 0.182 | 0.154 | 0.205 | −0.005 | −0.023 |
1IEP | 2.1 | 0.5 | 200 | 0.183 | 0.238 | 0.196 | 0.245 | −0.012 | −0.007 |
2XFA | 2.1 | 1.0 | 100 | 0.171 | 0.217 | 0.184 | 0.244 | −0.013 | −0.027 |
3ODU | 2.5 | 0.3 | 50 | 0.208 | 0.269 | 0.219 | 0.281 | −0.010 | −0.012 |
1M52 | 2.6 | 0.5 | 50 | 0.161 | 0.211 | 0.168 | 0.228 | −0.007 | −0.017 |
3CM8 | 2.9 | 0.5 | 67 | 0.194 | 0.235 | 0.205 | 0.248 | −0.011 | −0.013 |
3RZE | 3.1 | 0.1 | 72 | 0.210 | 0.280 | 0.210 | 0.291 | 0.000 | −0.011 |
Max | −0.051 | −0.049 | |||||||
Min | 0.000 | −0.003 | |||||||
Mean | −0.018 | −0.018 |
Rms (mFobs − DFmodel)exp[iφmodel] difference densities obtained from ensemble refinement and re-refinement in phenix.refine
PDB ID | Resolution (Å) | σmFo−DFc (e/Å3) | |
Ensemble | phenix.refine | ||
1KZK | 1.1 | 0.138 | 0.161 |
3K0M | 1.3 | 0.016 | 0.018 |
3K0N | 1.4 | 0.007 | 0.008 |
2PCO | 1.4 | 0.099 | 0.099 |
1UOY | 1.5 | 0.115 | 0.162 |
3CA7 | 1.5 | 0.132 | 0.148 |
2R8Q | 1.5 | 0.104 | 0.118 |
3QL0 | 1.6 | 0.124 | 0.138 |
1X6P | 1.6 | 0.098 | 0.105 |
1F2F | 1.7 | 0.104 | 0.126 |
3QL3 | 1.8 | 0.131 | 0.139 |
1YTT | 1.8 | 0.170 | 0.215 |
3GWH | 2.0 | 0.125 | 0.138 |
1BV1 | 2.0 | 0.109 | 0.119 |
1IEP | 2.1 | 0.084 | 0.091 |
2XFA | 2.1 | 0.069 | 0.074 |
3ODU | 2.5 | 0.105 | 0.113 |
1M52 | 2.6 | 0.088 | 0.093 |
3CM8 | 2.9 | 0.036 | 0.036 |
3RZE | 3.1 | 0.070 | 0.070 |
Effect of input structure on ensemble refinement. For three datasets ensemble refinement was performed using a starting structure from three different refinement programs. For each structure three …
PDB | Re-refinement | Ensemble refinement | |||||||||
Repeat 1 | Repeat 2 | Repeat 3 | Mean | ||||||||
Program | Rwork | Rfree | Rwork | Rfree | Rwork | Rfree | Rwork | Rfree | Rwork | Rfree | |
1UOY | Buster | 0.167 | 0.196 | 0.108 | 0.144 | 0.112 | 0.145 | 0.110 | 0.146 | 0.110 | 0.145 |
Refmac | 0.147 | 0.170 | 0.104 | 0.137 | 0.103 | 0.140 | 0.105 | 0.144 | 0.104 | 0.140 | |
Phenix | 0.155 | 0.185 | 0.109 | 0.142 | 0.109 | 0.147 | 0.111 | 0.149 | 0.110 | 0.146 | |
3CA7 | Buster | 0.177 | 0.208 | 0.137 | 0.186 | 0.137 | 0.192 | 0.141 | 0.197 | 0.138 | 0.192 |
Refmac | 0.170 | 0.205 | 0.139 | 0.187 | 0.135 | 0.189 | 0.138 | 0.193 | 0.137 | 0.189 | |
Phenix | 0.171 | 0.212 | 0.138 | 0.180 | 0.142 | 0.189 | 0.148 | 0.193 | 0.142 | 0.187 | |
1BV1 | Buster | 0.161 | 0.204 | 0.137 | 0.184 | 0.138 | 0.185 | 0.137 | 0.186 | 0.138 | 0.185 |
Refmac | 0.178 | 0.231 | 0.140 | 0.182 | 0.143 | 0.184 | 0.143 | 0.189 | 0.142 | 0.185 | |
Phenix | 0.154 | 0.205 | 0.139 | 0.188 | 0.138 | 0.189 | 0.140 | 0.189 | 0.139 | 0.189 |
Fmodel cross-correlation scores for ensembles generated with different input models. Three different refinement programs generated alternative starting structures, see Table 3. The best ensemble was …
PDB | Ensemble pair | CC | |
Re-refined input | Re-refined input | ||
1UOY | Refmac | Buster | 0.997 |
Refmac | Phenix | 0.997 | |
Buster | Phenix | 0.999 | |
3CA7 | Refmac | Buster | 0.993 |
Refmac | Phenix | 0.992 | |
Buster | Phenix | 0.996 | |
1BV1 | Refmac | Buster | 0.992 |
Refmac | Phenix | 0.990 | |
Buster | Phenix | 0.992 |
Comparison of three B-factor models for ensemble refinement. Burling et al. (Burling and Brunger, 1994) had shown previously that the choice of ADPs for ensemble refinement can affect the resultant …
PDB | Resolution (Å) | Global isotropic B-factor | Refined ADPs | Fitted TLS ADPs | |||||||
Rwork | Rfree | Wilson B-factor (Å2) | Global B-factor (Å2) | Rwork | Rfree | Scale factor | Rwork | Rfree | pTLS | ||
3K0M | 1.3 | 0.117 | 0.147 | 12.0 | 12.0 | 0.125 | 0.146 | 0.9 | 0.103 | 0.130 | 0.3 |
3K0N | 1.4 | 0.121 | 0.153 | 19.1 | 19.1 | 0.126 | 0.153 | 0.9 | 0.114 | 0.133 | 0.1 |
1UOY | 1.5 | 0.103 | 0.148 | 10.4 | 9.4 | 0.107 | 0.144 | 0.9 | 0.101 | 0.136 | 0.3 |
3CA7 | 1.5 | 0.129 | 0.194 | 16.8 | 13.4 | 0.142 | 0.192 | 0.9 | 0.142 | 0.190 | 0.5 |
1X6P | 1.6 | 0.108 | 0.158 | 15.9 | 12.7 | 0.113 | 0.152 | 0.8 | 0.121 | 0.150 | 0.8 |
1F2F | 1.7 | 0.116 | 0.184 | 15.6 | 14.8 | 0.123 | 0.167 | 0.8 | 0.126 | 0.167 | 0.7 |
1BV1 | 2.0 | 0.125 | 0.192 | 22.6 | 18.1 | 0.135 | 0.191 | 0.8 | 0.145 | 0.182 | 0.6 |
Mean | - | 0.117 | 0.168 | - | - | 0.125 | 0.164 | - | 0.122 | 0.155 | - |