Hi, I'm a student at National Taiwan University doing research on protein-ligand interactions using MD simulations with GROMACS (version 4.5.3). In our simulations, we placed a protein (group A) and a ligand (group B) in a box under periodic boundary condition and ran for 20ns.
I am trying to obtain snapshots of specific time frames within the trajectory file I got, but I am running into trouble outputting the exact position of the protein relative to the ligand when converting the frames into pdb files. Because of the period boundary condition, a snapshot may have the protein located on one side of the box and the ligand on the opposite end, but their actual relative positions---as measured by center of mass (COM) between specific region within the protein and the COM of the ligand----are in fact much closer to each other (1.33nm as calculated by GROMACS as part of the trajectory vs. 7.585nm after being converted into a pdb file). So my question is: How do I maintain the same exact positions of the protein and ligand in the extracted frame/pdb file as they were in the trajectory form? Thank you very much Wayne Chen -- View this message in context: http://gromacs.5086.n6.nabble.com/How-to-maintain-the-same-exact-positions-of-the-protein-and-ligand-in-the-extracted-frame-pdb-file-a-tp4998045.html Sent from the GROMACS Users Forum mailing list archive at Nabble.com. -- gmx-users mailing list gmx-users@gromacs.org http://lists.gromacs.org/mailman/listinfo/gmx-users Please search the archive at http://www.gromacs.org/Support/Mailing_Lists/Search before posting! Please don't post (un)subscribe requests to the list. Use the www interface or send it to gmx-users-requ...@gromacs.org. Can't post? Read http://www.gromacs.org/Support/Mailing_Lists