Hi Meshal, In Chimera 1.7 (the development version, daily build) there is a new feature to calculate average coordinates. To use this: (1) get the daily build of Chimera. <http://www.cgl.ucsf.edu/chimera/download.html#daily> (2) Start Chimera and open the NMR ensemble as a trajectory. You can fetch the PDB file like you already did, but then save it to a single PDB file and close the structure. Then re-open the single PDB file as a trajectory (start MD Movie from the Tools... MD/Ensemble Analysis menu, choose single-file PDB input format, browse to file location, open the file). <http://www.cgl.ucsf.edu/chimera/docs/ContributedSoftware/movie/framemovie.ht...> (3) In the MD Movie dialog menu, choose Analysis... Average structure. <http://www.cgl.ucsf.edu/chimera/docs/ContributedSoftware/movie/movie.html#av...> Note this is simple x,y,z coordinate averaging, and may produce a distorted structure. I hope this helps, Elaine ---------- Elaine C. Meng, Ph.D. UCSF Computer Graphics Lab (Chimera team) and Babbitt Lab Department of Pharmaceutical Chemistry University of California, San Francisco On May 5, 2012, at 12:51 AM, MESHAL ALMUALLIMI wrote:

Hello, How can I show only the average of my NMR solved structure? As when I fetch the PDBID 1YJR it shows all the structures aligned and I only need the average. I figured out how to eliminate as much structures as I can but I am interested in taking the average of all. Regards Meshal MS candidate Georgetown University