Effect of elastic bend distortions on electron diffraction data from thin protein microcrystals

Area of Science:

• Crystallography
• Materials Science
• Biophysics

Background:

• Electron diffraction is crucial for protein structure determination.
• Crystal distortions can introduce artifacts in diffraction patterns.
• Previous models accurately described diffraction from linear systems.

Purpose of the Study:

• Investigate the impact of elastic bend distortions in protein crystals on electron diffraction intensities.
• Assess the utility of high-resolution data for protein structure determination under such conditions.

Main Methods:

• Utilized a model calculation for rubredoxin.
• Employed an analytical expression derived by Cowley for kinematical diffraction.
• Analyzed the effect of crystal distortions on diffraction intensities.

Main Results:

• Elastic bend distortions significantly affect electron diffraction intensities.
• High-resolution data may not accurately represent the unit cell contents.
• The findings are dependent on the selected area size and beam coherence length.

Conclusions:

• Small selected areas or low beam coherence are necessary to mitigate distortion effects.
• High-resolution electron diffraction data may be unreliable for protein structure determination if distortions are present.
• Careful consideration of experimental parameters is vital for accurate structural analysis.