Orlova Elena V, Saibil Helen R
School of Crystallography, Birkbeck College, University of London, Malet Street, London WC1E 7HX, UK.
Curr Opin Struct Biol. 2004 Oct;14(5):584-90. doi: 10.1016/j.sbi.2004.08.004.
A new generation of electron microscopes equipped with field emission gun electron sources and the ability to image molecules in their native environment at liquid nitrogen or helium temperatures has enabled the analysis of macromolecular structures at medium resolution (approximately 10 angstroms) and in different conformational states. The amalgamation of electron microscopy and X-ray crystallographic approaches makes it possible to solve structures in the 100-1000 angstroms size range, advancing our understanding of the function of complex assemblies. Many new structures have been solved during the past two years, including one of the smallest complexes to be determined by single-particle cryo-electron microscopy, the transferrin receptor-transferrin complex. Other notable results include the near atomic level resolution structure of the nicotinic acetylcholine receptor in helical arrays and an icosahedral virus structure with an asymmetric polymerase resolved.
新一代配备场发射枪电子源的电子显微镜，能够在液氮或氦气温度下对天然环境中的分子进行成像，从而实现了对中等分辨率（约10埃）和不同构象状态的大分子结构的分析。电子显微镜和X射线晶体学方法的结合，使得解析100-1000埃尺寸范围内的结构成为可能，加深了我们对复杂组装体功能的理解。在过去两年中，已经解析出了许多新结构，包括通过单颗粒冷冻电子显微镜确定的最小复合物之一，转铁蛋白受体-转铁蛋白复合物。其他显著成果包括螺旋阵列中烟碱型乙酰胆碱受体的近原子水平分辨率结构，以及解析出具有不对称聚合酶的二十面体病毒结构。
