Dear Andrew, Thank you very much for the detailed instructions. I am downloading it Best Regards, Oarabile M. Kgosisejo [log in to unmask] ________________________________ From: Andrew Orry [[log in to unmask]] Sent: February 5, 2015 4:57 PM To: Kgosisejo, Oarabile; [log in to unmask] Subject: Re: [ccp4bb] Superposition of select residues The free ICM-Browser from MolSoft can do this - http://www.molsoft.com/icm_browser.html It will calculate the Ca-atom, backbone and heavy atom differences between multiple structures and superimpose. To do this: 1. Download and install ICM-Browser here (Win, Mac or Linux) http://www.molsoft.com/getbrowser.cgi 2. Read in the PDB structures using the search tab or File/Open 2. Select the residues in the proteins you wish to superimpose 3. Click on the superimpose button in the display tab - you can select one structure to be static. http://www.molsoft.com/gui/protein-structure-tutorials.html#protein-structure-tutorials-superimpose Thanks, Andrew -- Andrew Orry Ph.D. Senior Research Scientist MolSoft LLC 11199 Sorrento Valley Road San Diego, CA 92121 -- Tel: 858-625-2000 x108 Fax: 858-625-2888 www.molsoft.com<http://www.molsoft.com> www.twitter.com/MolSoft<http://www.twitter.com/MolSoft> On 2/5/2015 2:41 PM, Kgosisejo, Oarabile wrote: Hi all, Does anyone know of a program to use to superpose only selected protein residues, e.g. enzyme active site residues. I solved my structure using molecular replacement now I want to compare its active site to those of homologous structures. I have used the DALI server before but I had to upload the whole model. Thank you for your advise Best Regards, Oarabile M. Kgosisejo, MSc. Candidate University of Saskatchewan [log in to unmask]<mailto:[log in to unmask]>