Department of Physics, University of Illinois, Urbana-Champaign, Urbana, IL 61801, USA.
Biopolymers. 2012 Sep;97(9):678-86. doi: 10.1002/bip.22042.
The increasing power and popularity of cryo-electron microscopy (cryo-EM) in structural biology brought about the development of so-called hybrid methods, which permit the interpretation of cryo-EM density maps beyond their nominal resolution in terms of atomic models. The Cryo-EM Modeling Challenge 2010 is the first community effort to bring together developers of hybrid methods as well as cryo-EM experimentalists. Participating in the challenge, the molecular dynamics flexible fitting (MDFF) method was applied to a number of cryo-EM density maps. The results are described here with special emphasis on the use of symmetry-based restraints to improve the quality of atomic models derived from density maps of symmetric complexes; on a comparison of the stereochemical quality of atomic models resulting from different hybrid methods; and on application of MDFF to electron crystallography data.
冷冻电子显微镜（cryo-EM）在结构生物学中的功能日益强大且普及，催生了所谓的混合方法，这些方法可以根据原子模型来解释超出冷冻电子显微镜密度图名义分辨率的信息。2010 年冷冻电子显微镜建模挑战赛是首次将混合方法的开发者以及冷冻电子显微镜实验者聚集在一起的一次社区活动。在挑战赛中，分子动力学灵活拟合（MDFF）方法被应用于许多冷冻电子显微镜密度图。本文将对这些结果进行描述，重点介绍利用基于对称的约束来提高源自对称复合物的密度图的原子模型质量；不同混合方法得出的原子模型的立体化学质量的比较；以及 MDFF 在电子晶体学数据中的应用。
