I put a tool on the Chimera experimental features web page that enhances the standard rotation and translation mouse modes (left and middle mouse buttons) to enable moving helices, strands, turns, PDB chains, any selected set of atoms, or multiscale model chains. http://www.cgl.ucsf.edu/chimera/experimental/experimental.html The molecular pieces are translated or rotated by dragging them with the mouse. It requires Chimera version 1.2206 or newer, and that is only available for Macintosh computers right now. Tom