Abstract
Graphic display systems are steadily becoming a tool in the field of molecular structural (conformational) analysis. Comparison of the features of many working systems in U. S. A. and UK made by G. R. Marshall et al. of Washington University, U. S. A. (in Computer Representation and Manipulation of Chemical Information, p. 203 (1974) John Wiley & Sons) is shown to understand the present status of the method. From the viewoint of application to X-ray crystallography, presentation of electron density maps made by T. H. Gossling at the Medical Research Council Laboratory of Molecular Biology, UK, (Acta Cryst. 22, 465 (1967) ) is also very important and useful. Besides, as a subsidiary tool of packing analysis, the system at the Princeton University Computer Graphics Laboratory, U. S. A., has been used to solve the structure of Guanosine-3', 5'-cytidine monophosphate by R. Langridge and his coworkers (Biopolymers, 12, 2731 (1974) ) . Using the accumulated information of protein crystallography and chemical sequence of proteins, the system at the Electrotechnical Laboratory in Tokyo, Japan, has been used to challenge the prediction of the tertiary structure of a protein by the present author.
