Peak Performance: Advances in Macromolecular MicroED Data Collection

TL;DR

New technologies in electron crystallography improve data quality, enabling high-resolution structural models from small biological nanocrystals.

Contribution

Advances in hybrid pixel and direct electron detectors, along with energy filtering, enhance MicroED data collection for higher resolution.

Findings

Hybrid pixel and direct electron detectors reduce read-out noise and improve signal-to-noise ratios in diffraction data.

Energy filtering sharpens diffraction peaks by removing inelastically scattered electrons, improving resolution.

Improved data collection strategies enable more accurate intensity measurements and better structural models.

Abstract

High-resolution data and accurate intensity measurements are crucial for resolving detailed structural models in macromolecular electron crystallography. However, obtaining high-quality structural information at atomic resolution is generally difficult, especially for crystalline biological specimens, as the diffracted intensities rapidly fade at higher resolution. Increasing the fluence does not circumvent this problem, as it results in detrimental radiation damage that compromises data quality. The diffraction signal at low flux density conditions is therefore generally expected to be relatively weak, limiting the attainable resolution. Recent advances in macromolecular MicroED data collection have substantially improved data quality, making it possible to extract high-resolution information from small nanocrystals that would otherwise be difficult to analyze. Notably, the introduction of hybrid pixel detectors and direct electron detectors has revolutionized diffraction data acquisition. These cameras essentially have no read-out noise and greatly improve the signal-to-noise ratio, which is particularly beneficial for recording reliable data from faint high- resolution reflections. In many cases, data quality and resolution can further be improved using energy filtering, which decreases background noise and sharpens diffraction peaks by removing inelastically scattered electrons. These technological advances allow for improved data collection strategies, enabling more accurate intensity measurements at higher resolution. Better data leads to better structural models that provide deeper insights into protein structure and function.