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

The effect of small elastic bend distortions in thin protein crystals on electron diffraction intensities is investigated using a model calculation for rubredoxin. The calculation, based on analytical expression derived by Cowley, has been shown previously to give an almost quantitative description of kinematical diffraction from linear chain systems. It is therefore shown that, unless the selected area used in the electron diffraction experiment is very small (or alternatively the incident beam has a small coherence length), the high resolution data may not be useful for structure determination, since they do not represent the total contents of the unit cell.