I am trying molecular replacement with a very poor model. The model consists mainly of 1 long helix and two slightly bent antiparallel helices. After dividing it into 2 fragments, I was able to find a solution for one of the fragments ( at least I think so after looking at maps, packing, refinement etc). But even if I place the first solution as fixed ensemble in phaser, I cannot find a solution for the second fragment ( 18% sequence identity). From the structure of the model and the packing it seems clear where the fragment should go roughly.
Are there any other programs other than phaser that might be able to solve this problem? I tried already epmr and mr_rosetta without success. I also tried to just superimpose the complete model onto the partial solution. This results in quite nice packing, but doesn't refine. Is there a rigid program refinement program with very large convergence? Ursula -- Ursula Schulze-Gahmen, Ph.D. Project Scientist UC Berkeley, QB3 360 Stanley Hall #3220 Berkeley, CA 94720-3220 (510) 643 9491
