The separation of the effects of atomic displacement and local resolution in crystallographic and cryo-electron microscopy maps

Abstract

Uncertainties in atomic coordinates and loss of resolution blur atomic images on density maps. The resolution cutoff leads to an additional effect, the appearance of Fourier ripples. Ignoring these ripples makes it impossible to distinguish between the two sources of image blurring. However, separate determination of the atomic displacement parameter and local resolution becomes possible if an advanced method for calculating the image of the atom in the observed map is used, which includes modeling of ripples. SynopsisShell-based density modelling allows us to separate the effects of atomic displacement and of resolution cutoffs in crystallographic and cryo-electron microscopy maps during refining atomic models in real space.