I read a lot of articles about techniques for the crystallization of Photosystem I and II from cyanobacteria. My question is what is the reason for that and what can you do with Photosystem crystals?
The main purpose of crystallizing a molecule or molecular complex like a Photosystem is usually to provide a crystal for X-ray crystallography. A crystal has its molecular components arranged in a structured systematic repeating pattern, and this repeated pattern allows the X-rays to reveal the 3-dimensional shape of one of the components. Knowing the shape is of biological interest as it suggests how the molecules perform their function.