To Whom This May Concern: In previous discussions, you explained how you could append two PDB files through the "join models" function: Discussion: <http://www.cgl.ucsf.edu/pipermail/chimera-users/2011-April/006245.html> Build Structure: <http://www.cgl.ucsf.edu/chimera/docs/ContributedSoftware/editing/editing.html#join> I would like attach a second PDB file to an initial one as well. However, my primary PDB file is a tetramer, made up of four identical chains. I would like to attach the second PDB to each of the four chains at the C-terminus. Is this possible? If so, how would I go about this? My concern is that using the "join models" function, it will only append the second PDB file once to the whole structure instead of to each individual chain. Cheers, Carl