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.
structural determination of micron-sized crystal SUMMARY
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