Hello Anjana, Are you sure you're using Chimera? As far as I know there is no APBS plugin for Chimera, only for Pymol. In Chimera, (A) there are several ways to show distances, including selecting two atoms (Ctrl-click on one atom, Shift-Ctrl-click on the second atom) and using command: distance sel (B) there is no tool especially for aromatic interactions, but you can use the tool Find Clashes/Contacts or command findclash to identify contacts between two sets of aromatic residues. For example, to identify contacts between aromatic amino acids in chain A and aromatic amino acids in chain B, command: findclash :.a&aromatic test :.b&aromatic overlap -1 hb 0 (You would probably also want to display all atoms so you can see where the contacts are.) The same thing could be done using the Find Clashes/Contacts graphical interface, in the menu under Tools... Structure Analysis. GUI documentation: <http://www.cgl.ucsf.edu/chimera/docs/ContributedSoftware/findclash/findclash.html> Command documentation: <http://www.cgl.ucsf.edu/chimera/docs/UsersGuide/midas/findclash.html> 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 Jan 4, 2012, at 9:02 PM, Anjana Ramnath wrote:

Hello all, My question is simple: im trying to install the APBS plugin but have so far been unsuccessful. I am also trying to show the interactions between aromatic residues on a PDB molecule. how do i do this? im also having trouble with showing the distance between 2 residues. im using Fedora 12 and also WindowsXP. please do let me know. thank you very much! sincerely, Anjana.