Orienting the future of bio-macromolecular electron microscopy

摘要

With 40 years of development,bio-macromolecule cryo-electron microscopy (cryo-EM) has completed its revolution in terms of resolution and currently plays a highly important role in structural biology study.According to different specimen states,cryo-EM involves three specific techniques:single-particle analysis (SPA),electron tomography and subtomogram averaging,and electron diffraction.None of these three techniques have realized their full potential for solving the structures of bio-macromolecules and therefore need additional development.In this review,the current existing bottlenecks of cryo-EM SPA are discussed with theoretical analysis,which include the air-water interface during specimen cryo-vitrification,bio-macromolecular conformational heterogeneity,focus gradient within thick specimens,and electron radiation damage.Furthermore,potential solutions of these bottlenecks worthy of further investigation are proposed and discussed.