GRAPICAL USER INTERFACE FOR PHASES RUNNING ON A PC. Akihito Yamano and Yukiteru Katsube, X-ray Research Laboratory, Rigaku Corporation, 3-9-12 Matubara, Akishima, Tokyo 196, Japan

PHASES software package¹⁾ has been one of the popular choice among protein crystallographers to obtain initial phases out of isomorphous replacement data sets. Although the software accompanies an easy-to-read document and is well organized, it has been developed for workstations and basically a command based program. Considering the rapid development of hardware and software of IBM/AT compatible PCs, we decided to port PHASES to a PC and to create a graphical user interface (GUI) to enhance the capability of the package. The interface is actually speeding up the process of evaluating isomorphous replacement data and producing maps at our lab.

The GUI consists of a drawing area on the right and a command/information area on the left. It has the following features. (1) No need to edit or typing-in data and instructions. Preparation and execution are done by using a mouse. (2) Results are displayed in the drawing area as graphs and tables, while a log file is typed in a window in the information area. One can judge the result visually. (3) It is taking the full advantage of SHELXS-86²⁾ running on a PC to determine heavy atom positions. The result of the direct method is compared with an isomorphous or anomalous difference Patterson map to validate the solution. Using SHELXS is much faster than interpreting Patterson maps. (4) One can further confirm the heavy atom positions by executing translational correlation search. (5) The interface is written in Microsoft Visual C++ and has a look common in any other Windows95 applications. Therefore, one can get use to the interface very easily. (6)The entire PHASES package was ported to PC with no modifications. Therefore, input files constructed on a workstation before can be used with this PC version of PHASES.

The interface and PC-PHASES will be presented with some examples including Phospholipase A₂ data sets that have been analyzed at Rigaku.

[1] Furey, W. and Swaminathan, S. (1990) PHASES - A program package for the processing and analysis of diffraction data sets for macromolecules. Am. Crystallogr. Assoc. Meet. Program Abstract 18.73.

[2] Sheldrick G.M. (1985) SHELXS86. Program for the Solution of Crystal Structures. University of Goettingen, Germany.