A Multi-model Approach to Assessing Local and Global Cryo-EM Map Quality.
- Author(s): Herzik, Mark A, Jr
- Fraser, James S
- Lander, Gabriel C
- et al.
Published Web Locationhttps://www.ncbi.nlm.nih.gov/pubmed/?term=30449687
There does not currently exist a standardized indicator of how well cryo-EM-derived models represent the density from which they were generated. We present a straightforward methodology that utilizes freely available tools to generate a suite of independent models and to evaluate their convergence in an EM density. These analyses provide both a quantitative and qualitative assessment of the precision of the models and their representation of the density, respectively, while concurrently providing a platform for assessing both global and local EM map quality. We further use standardized datasets to provide an expected deviation within a suite of models refined against EM maps reported to be at 5 Å resolution or better. Associating multiple atomic models with a deposited EM map provides a rapid and accessible reporter of convergence, a strong indicator of highly resolved molecular detail, and is an important step toward an FSC-independent assessment of map and model quality.