Quantifying the local resolution of cryo-EM density maps

• Published in: Nature methods Vol. 11; no. 1; pp. 63 - 65
• Main Authors: Kucukelbir, Alp, Sigworth, Fred J, Tagare, Hemant D
• Format: Journal Article
• Language: English
• Published: New York Nature Publishing Group US 01.01.2014; Nature Publishing Group
• Subjects: 631/114/1564; 631/114/794; 631/1647/2258/1258/1259; 631/45/612; Algorithms; Alleles; Bioinformatics; Biological Microscopy; Biological Techniques; Biomedical Engineering/Biotechnology; brief-communication; Cryoelectron microscopy; Cryoelectron Microscopy - methods; Fourier Analysis; Image processing systems; Imaging, Three-Dimensional; Life Sciences; Likelihood Functions; Microscopy; Models, Theoretical; Normal Distribution; Optics; Proteins; Proteins - chemistry; Proteomics; Resolution (Optics); Ribosomes - chemistry; Scientific imaging; Software; Viruses - chemistry
• ISSN: 1548-7091; 1548-7105; 1548-7105
• DOI: 10.1038/nmeth.2727

A method and software tool, ResMap, for quantifying the local resolution across 3D electron cryo-microscopy density maps is reported. We propose a definition of local resolution for three-dimensional electron cryo-microscopy (cryo-EM) density maps that uses local sinusoidal features. Our algorithm has no free parameters and is applicable to other imaging modalities, including tomography. By evaluating the local resolution of single-particle reconstructions and subtomogram averages for four example data sets, we report variable resolution across a 4- to 40-Å range.