Making the Invisible Visible
A Rare Lysozyme Crystal Form Solved Using Highly Redundant Multiple Electron Diffraction Datasets from Micron-Sized Crystals
Researchers from Stockholm University solved the structure of lysozyme from micro-crystals with a rare crystal form using ASI’s sensitive detector technology. Due to the detectors’ high read-out speed, in a short time, multiple datasets could be collected improving the final model quality.
Recent developments of novel electron diffraction techniques have shown to be powerful for determination of atomic resolution structures from micron and nano-sized crystals, too small to be studied by single-crystal X-ray diffraction. In this work, the structure of a rare lysozyme polymorph is solved and refined using continuous rotation MicroED data and standard X-ray crystallographic software. Data collection was performed on a standard 200 kV transmission electron microscope (TEM) using a highly sensitive detector with a short readout time.
The data collection is fast (3 min per crystal), allowing multiple datasets to be rapidly collected from a large number of crystals. We show that merging data from 33 crystals significantly improves not only the data completeness, overall I/s and the data redundancy, but also the quality of the final atomic model. This is extremely useful for electron beam-sensitive crystals of low symmetry or with a preferred orientation on the TEM grid.
The full article can be found on the Science Direct website
Image courtesy of Xu et. al. Structure DOI: (10.1016/j.str.2018.02.015), Copyright © 2018 Elsevier Ltd