Study of Protein Three Dimensional Structures -A study of three dimensional structure of a protein (including a study of active sites) is the first step in any exercise on protein engineering. For such a study, protein should be available in crystal form. X- ray diffraction methods have also been developed to generate data at a fast rate, to enable us to predict the three dimensional structure of the proteins through model building.

Observed differences in structures of different enzymes can be related with the differences in their functions, so that the knowledge from such studies can be used for protein engineering. X-ray diffraction data at different temperatures also allow us to learn about the changes expected in protein structure due to change in temperature suggesting that the protein structure is dynamic.