 |
 |
Perhaps obvious - are you sure the space group is C222 not C2221? Phil On 25 Jul 2008, at 14:19, Roger Rowlett wrote: > Carl Soja wrote: >> Dear all >> I tried to solve one structure by ccp4i molrep(resolution at 3.0 A, >> space group C222, sequence ID 30%). I can get a good Rfactor 0.528 >> at first translation function. However, the second translation >> function Rfac is 0.526, the third is 0.525, the fourth is 0.525. >> All of the translation function Rfacs are too closed. I changed >> the model and minimum resolution for search, the Rfactor closed no >> any improved. My structure estmates four molecules in the >> aymmetric unit. This is my first time found the closed Rfac by >> molrep. From the low translation function Rfac, it seems that it >> is correct solution. I checked the solution and found some clashes >> in the structure.I am not sure why the Rfactor too closed in next >> the molecule search? I know this is unusual solution by molrep. >> Does it mean the diffraction data has problem? >> Any suggestions are welcome.Thank you in advance! >> Carl soja > To be honest, I would try both Phaser and EPMR (now Open-EPMR) first > to do MR. Both especially excel at finding good MR solutions for > multimers, and are very fast as well. These programs can find > solutions that are very difficult to find using other rotation- > translation programs, including MOLREP. In my experience (using > Phaser and EPMR) reasonable MR solutions almost always have an R- > factor under 50%. > > Cheers, > > > -- > ------------------------------------------------------------------------ > Roger S. Rowlett > Professor > Colgate University Presidential Scholar > Department of Chemistry > Colgate University > 13 Oak Drive > Hamilton, NY 13346 > > tel: (315)-228-7245 > ofc: (315)-228-7395 > fax: (315)-228-7935 > email: [log in to unmask]