Hi Thomas, There isn't a keyboard shortcut except selection undo (left arrow, only remembers one previous state), but if I understand you correctly there are some possibilities for making your life easier: (a) you can name a selection with "Select... Name Selection" (or command namesel) and then later simply use that name in commands or re- select it with "Select... Named Selections... [name]" <http://www.cgl.ucsf.edu/chimera/docs/UsersGuide/midas/namesel.html> (b) if it is something that can be described with a command-line atom specification string, you can avoid selecting altogether and just alias the specification. The alias can then be used in subsequent commands. <http://www.cgl.ucsf.edu/chimera/docs/UsersGuide/midas/alias.html> For example: alias inhibitor :/isHet & ~ solvent show inhibitor alias sheetset :25-38,127-136,145-170,196-212 ribbon sheetset alias sheeta sheetset & :.a color dodger blue sheeta Thanks for the holiday wishes -- Merry Christmas to you too! 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 Dec 23, 2009, at 1:16 AM, Dipl.-Ing. Thomas Mitterfellner wrote:

Hello! I'd like to group a certain set of bonds (or atoms), so that I can select them quickly without having to select each item manually every time I decide to change a property like size, style or color. I know that selecting a pseudobond and pressing the UP key selects all pseudobonds. Is it possible to do that for a user-defined subset of bonds too? Thank you, Thomas

P.S.: Merry Christmas to the Chimera team!