If it is a _true_ 4.5 A resolution map, you should be able to build alpha-helices and beta strands (can buccaneer do that automatically in at 4.5A?) and then use these secondary structure elements to find your known structures.
Foldhunter from EMAN should be able to build helices and strands automatically. UCSF Chimera either comes with EMAN extensions or they can be added and one can run hunter directly in Chimera: http://ncmi.bcm.tmc.edu/software/AIRS You can also try Situs: http://situs.biomachina.org/ If the map is good, Situs works like a charm. Cheers, Petr From: CCP4 bulletin board [mailto:ccp...@jiscmail.ac.uk] On Behalf Of Peter Grey Sent: Tuesday, March 30, 2010 12:20 AM To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] Fitting high resolution structures to low resolution map Dear All, I have a crystal (not EM) density map of a very large complex at 4.5A resolution. I have pdb files for homologs of a few of the subunits of this huge complex. I would like to fit these homologs into the density. I have tried without success so far programs that handle phased molecular replacement - MOLREP, ESSENS and FFFEAR. Could you please suggest other programs or servers that can tackle this problem ? Many thanks, Peter
