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Figure 3
Cumulative distributions for properties of loops that can be built in the PDB. (Left) Most of the buildable loops are short. (Middle) Density ratio of loop candidates; in contrast to the other two subfigures, this includes loops that were not built. This metric represents the observed density for the loop main chain divided by the average main-chain density. The minimum required density ratio of 0.25 is indicated by the vertical red line. Of all initial loop candidates, 60% have insufficient density and are therefore discarded. (Right) The Ramachandran Z score for candidate loops and their counterparts in the structure model from which they were taken. The backbone conformation of the built loops is excellent and better than the conformation of loops in structures from which they were taken, which is largely a result of the application of Ramachandran restraints in the real-space refinement of loops in coot-mini-rsr (Emsley et al., 2010BB15).

IUCrJ
Volume 5| Part 5| September 2018| Pages 585-594
ISSN: 2052-2525
https://doi.org/10.1107/S2052252518010552