Figure 2
Issues in map tracing and additional constraints. (a) The trace corresponding to an electron-density map of the coiled coil autophagy-related protein 38 at 2.4 Å resolution illustrates how the helical geometry is degraded in the regions where the map is poor. (b) shows how an originally placed seed (lime) continuing a correct seed (red) is refined by the unrestrained simplex into the density of a neighbouring helix (purple). The neighbouring helix happens to be in the reversed direction. (c) Seed coverage in the first autotracing cycle of fibronectin for the unrestrained versus (d) restrained simplex refinement of β-sheets. In (c) and (d) the sequence numbers increase from left to right and the r.m.s.d. of the seeds versus the correct structure is represented in blue (<0.36 Å), green (0.5 Å) and yellow (<1 Å). Restraining the simplex refinement of the seeds (d) renders a better and more accurate coverage than in (c). |