Advances In Computer Aided Protein Structure Determination From Sparse Cryo Electron Microscopy Data

Abstract

Single-particle cryo-electron microscopy (cryoEM) has become a powerful tool for determining macromolecular structures. Thanks to recent advances in direct electron detectors and motion correction algorithms it can frequently deliver electron density maps in the range of 3-5Å resolution. To obtain as much atomic level detail of the structure as possible from this data an accurate atomic model must be built. This can be done manually however, it is laborious and error prone. To resolve this problem modelers have turned to computational tools which can make up for lack of experimental data. Here we describe several tools for modeling with sparse experimental data, including a novel sampling strategy for de novo model completion and a novel refinement strategy for glycans with near atomic resolution cryoEM and x-ray crystallography data.