Abstract
Since the first application of X-ray diffraction study for the structure determination of bacterial photosynthetic reaction center, it has turned out that the technique can be utilized for high-resolution structural analysis of various types of membrane protein. Cryo-electron microscopy has also contributed to the structural studies on membrane proteins which rarely assembled into three-dimensional crystal. A number of remarkable findings obtained by these techniques are summarized. Some interesting topics for the future researches are also pointed out, including expected application of another technique such as atomic force microscopy (AFM).
