Figure 3.

Results from paired refinement for EP (a)–(c), POLI (d)–(f) and BO (g)–(i). Note for bar charts showing the differences in the overall R values: for each incremental step of resolution for X→Y, the R values were calculated at resolution X. EP: (a) differences in the overall R values; resolution shells with a width of 0.05 Å were added stepwise. A systematic decrease in R _free was observed up to 1.20 Å. (b) CC* remains higher than CC_work in the whole resolution range for all the refined models. (c) Improvement in electron-density quality of the partially occupied fragment B53. Omit maps after refinement up to 1.44 (magenta) and 1.20 Å (green) are contoured at a level of 0.56 e Å⁻³. Atomic positions of the fragment molecule originate from PDB entry 4y4g (Huschmann et al., 2016 ▸). The graphic was rendered in CCP4mg (McNicholas et al., 2011 ▸). POLI: (d) differences in the overall R values; resolution shells with a width of 0.10 Å were added stepwise. (e) Comparison of CC* and CC_work of refined models. (f) R _work of refined models. The level R _work = 0.42 is shown as a red line. BO: (g) differences in the overall R values; resolution shells with a width of 0.10 Å were added stepwise. (h) Comparison of CC* and CC_work of refined models. (i) 〈I/σ(I)〉 and CC_1/2 of the diffraction data depending on resolution; the level 〈I/σ(I)〉 = 2 is shown as a red line.