Dear Ursula, If you have a resolution around 2.0 A you can try some of the following:
- Expand the partial solution with shelxe autotracing feature. - Do a search with ARCIMBOLDO_LITE using the partial solution. You can fin the program at http://chango.ibmb.csic.es/arcimboldo_lite. Then, instead of searching for ideal alpha helices, you can input your solution and search for 2 copies. Hope it helps. Best, Claudia ---------------------------------------------------------------------------------------- Claudia Millán (cmn...@ibmb.csic.es) Crystallographic Methods Group http://chango.ibmb.csic.es Institut de Biologia Molecular de Barcelona (IBMB-CSIC) Barcelona, Spain LinkedIn: es.linkedin.com/in/claudiamillan/ <http://es.linkedin.com/pub/claudia-mill%C3%A1n/60/a76/821/> ResearchGate: https://www.researchgate.net/profile/Claudia_Millan?ev=hdr_xprf 2014-12-12 22:38 GMT+01:00 Ursula Schulze-Gahmen <uschulze-gah...@lbl.gov>: > > 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 >
