FIG. 1.

Local density variation at helix regions and the problem of evaluation between a set of points and the atomic model of a helix. The density (gray) at the helix location is superimposed with the atomic model (blue ribbon). The EMDB ID and the PDB ID are labeled for two cases in (A) and (B). (C) The set of points (red) in the approximate location of the helix axis is assigned to the density map. The location of the helix axis (green) was calculated from the atomic model (blue ribbon). EMDB, Electron Microscopy Data Bank; PDB, Protein Data Bank.