MonoRes: Automatic and Accurate Estimation of Local Resolution for Electron Microscopy Maps

Jose Luis Vilas; Josué Gómez-Blanco; Pablo Conesa; Roberto Melero; José Miguel de la Rosa-Trevín; Joaquin Otón; Jesús Cuenca; Roberto Marabini; José María Carazo; Javier Vargas; Carlos Oscar S Sorzano

doi:10.1016/j.str.2017.12.018

MonoRes: Automatic and Accurate Estimation of Local Resolution for Electron Microscopy Maps

Structure. 2018 Feb 6;26(2):337-344.e4. doi: 10.1016/j.str.2017.12.018. Epub 2018 Jan 27.

Affiliations

¹ Biocomputing Unit, National Center for Biotechnology (CSIC), Darwin 3, Campus Universidad Autónoma, Cantoblanco, 28049 Madrid, Spain. Electronic address: jlvilas@cnb.csic.es.
² Biocomputing Unit, National Center for Biotechnology (CSIC), Darwin 3, Campus Universidad Autónoma, Cantoblanco, 28049 Madrid, Spain.
³ Science for Life Laboratory, Stockholm University, Stockholm, Sweden.
⁴ Escuela Politécnica Superior, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain.
⁵ Biocomputing Unit, National Center for Biotechnology (CSIC), Darwin 3, Campus Universidad Autónoma, Cantoblanco, 28049 Madrid, Spain. Electronic address: carazo@cnb.csic.es.
⁶ Department of Anatomy and Cell Biology, McGill University, University Street Strathcona Anatomy Building, 3640 Montreal, Canada.
⁷ Biocomputing Unit, National Center for Biotechnology (CSIC), Darwin 3, Campus Universidad Autónoma, Cantoblanco, 28049 Madrid, Spain; Department of Engineering of Electronic and Telecommunication Systems, Universidad San Pablo-CEU, Campus Urbanización Montepríncipe, Boadilla del Monte, 28668 Madrid, Spain. Electronic address: coss@cnb.csic.es.

PMID: 29395788
DOI: 10.1016/j.str.2017.12.018

Abstract

Since the beginning of electron microscopy, resolution has been a critical parameter. In this article, we propose a fully automatic, accurate method for determining the local resolution of a 3D map (MonoRes). The foundation of this algorithm is an extension of the concept of analytic signal, termed monogenic signal. The map is filtered at different frequencies and the amplitude of the monogenic signal is calculated, after which a criterion is applied to determine the resolution at each voxel. MonoRes is fully automatic without compulsory user parameters, with great accuracy in all tests, and is computationally more rapid than existing methods in the field. In addition, MonoRes offers the option of local filtering of the original map based on the calculated local resolution.

Keywords: electron microscopy; local resolution; single particle analysis.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Algorithms
Computer Simulation
Cryoelectron Microscopy / methods*
Image Processing, Computer-Assisted / methods*
Models, Molecular*
Software