-=-=-=-=--=-=-=-=-=-=-=-=-= MORASS version 2.1 -=-=-=-=-=-=-=--=-=-=-= MORASS - Multiple Overhauser Relaxation AnalysiS and Simulation - uses a full hybrid matrix eigenvalue/eigenvector solution to the Bloch equations to derive cross-relaxation rates and interproton distances. MORASS analyzes 2D NMR NOESY data from oligonucleotides and proteins to evaluate cross-relaxation rates from which interproton distances are obtained. These are output in a format suitable for use as distance constraints in molecular dynamics calculations. MORASS is interfaced to work well with CHARMM and AMBER (most of our work has been done with AMBER). Certainly any other MD package would be suitable after a little 'fiddling' with the formats - contact me for details if necessary. MORASS also calculates a NOESY spectrum given a model structure including proton coordinates (e.g. a .pdb file). MORASS 2.1 will now produce output suitable for display using the graphics package GRASP. With GRASP, NOESY constraint differences can be displayed with a .pdb file as pair-wise interactions (constraint differences being the difference between the theoretical NOESY derived interproton distances and the distance calculated from the .pdb file). The constraint diffs are shown as color-coded cylinders between the two sites and the width of the cylinders can be easily made proportional to the magnitude of the difference. The color coding is a convenient way of visualizing the magnitude of the difference by segmenting it into ranges which are indexed by color. We find this to be an extremely intuitive way of visualizing the convergence of the NOESY refined structural determination and it has speeded up our work a great deal. GRASP modified to accept MORASS input is available from Dr. Anthony Nicholls in Barry Honig's group at Columbia Universiy (nicholls@cuhhca.hhmi.columbia.edu). The MORASS 2.1 documentation is written in LaTeX. Please contact us if you require something different. Note that MORASS 2.1 has many additions over MORASS 1.0 and 2.0. Virtually all MORASS 1.0 and 2.0 is incorporated in MORASS 2.1 and any earlier MORASS input file should run error-free on version 2.1 . Comments and suggestions are always welcome. Please feel free to use this software as you like but please provide the following reference: R.Meadows, C.B.Post, B.A.Luxon and D.G.Gorenstein, MORASS 2.1 Program, Purdue University, W. Lafayette (1994). Please do not distribute this software yourself but do feel free to point others to the MORASS distribution in our ftp anonymous. This insures that only the most up to date software and documentation is distributed and gives us some record of who is getting what. Assistance will be cheerfully rendered but keeping within the free context, it may be a little slow at times if we are particularly busy. We run MORASS on SGI Irix 4.04 & 4.0.5H, IBM RS6000, DEC Ultrix & VAX and Sun 4-110. It may compile on others but I'm personally not familiar with them. If you publish an article or present a paper on results using MORASS, a copy would be very much appreciated. TO RUN MORASS YOU NEED TO GET - > morass21.tar.Z and YOU MAY ALSO WISH TO GET - > ../flatwell/flatwell.tar.Z - AMBER flatwell potential code > cshift/cshift.tar.Z - Chemical shift routine > ../util/util/tar.Z - AMBER and MORASS utilities > testout/testout.tar.Z - output files from the test input CONTENTS of .tar FILE INCLUDE - o Source code in Fortran o Makefiles for SGI, IBM RS6K and DEC Ultrix o Documentation in LaTeX format o Sample input files o Sample output files o GRASP - MORASS .rgb sample files BRUCE A. LUXON CHEMISTRY DEPT. PURDUE UNIVERSITY W. LAFAYETTE, IN 47907 e-mail: bruce@dggpi2.chem.purdue.edu (317) 494-5289