期刊名称：Lecture Notes in Engineering and Computer Science
印刷版ISSN：2078-0958
电子版ISSN：2078-0966
出版年度：2018
卷号：2231&2232
页码：63-68
出版社：Newswood and International Association of Engineers
摘要：Cryo-electron microscopy and other imaging
technique opened a new window to the analysis of large
biomolecular assemblies under biologically relevant conditions.
In most cases, electron microscopy maps have low resolution
and high noises. Such low-resolution maps do not have enough
information to uniquely determine atomic structures of
macromolecular systems. The map-restrained self-guided
Langevin dynamics (MapSGLD) method we developed
previously can utilize structural information embedded in a
force field to flexibly fit macromolecular systems into low
resolution maps to obtain energetically favored atomic
structures that satisfy the maps. Using glutamate receptor as an
example, we describe how to perform flexible fitting with
MapSGLD to obtain atomic structures from EM maps. The
open state atomic structure of the glutamate receptor shows the
LBD in the clamshell closed conformation that agrees with the
LBD x-ray structure. Most importantly, our MapSGLD flexible
fitting structure captures the open state ion channel, which has
not been observed so far in x-ray structures.
