2-DIMENSIONAL CRYSTALLIZATION OF PROTEINS ON PLANAR LIPID FILMS AND STRUCTURE DETERMINATION BY ELECTRON CRYSTALLOGRAPHY

Electron crystallography constitutes a powerful new method for determi ning the struture of biological macromolecules. This method is best ad apted to the study of ordered assemblies of macromolecules, and princi pally to two-dimensional (2-D) crystals of proteins. Obtaining protein 2-D crystals ordered at high resolution constitutes the major limitin g step in the application of this approach. Considerable interest has been raised by the development of a rational method of 2-D crystalliza tion based on the specific binding of proteins to planar lipid films. The applicability of this method is quasi-general in the case of solub le proteins. Its basic principles, together with examples taken from w ork in our group, are presented here.