Hi Kevin, The command "turn x 23" will rotate active models about the screen x axis by 23 degrees. The command "turn 1,1,0 180 center 0,2.5,2.5 coord #1 models #1" rotates just model #1 by 180 degrees about axis 1,1,0 defined in the local coordinates of model #1 about center point 0,2.5,2.5 also in model #1 local coordinates. The fancier forms of the turn command are only in Chimera 1.4 daily builds. http://www.cgl.ucsf.edu/chimera/docs/UsersGuide/midas/turn.html You align multiple structures by aligning them all to one reference structure. You can align specific residues with the "match" command: http://www.cgl.ucsf.edu/chimera/docs/UsersGuide/midas/match.html Do do a sequence based structure alignment look at the MatchMaker tool or command: http://www.cgl.ucsf.edu/chimera/docs/ContributedSoftware/matchmaker/matchmak... Best to send questions to chimera-users@cgl.ucsf.edu. Tom Kevin Koehntop wrote:

Hi Tom,

In Chimera, how do you rotate a structure along an axis by X degrees? How is the specific axis selected? Finally, is it possible to align multiple structures (e.g. their tops, bottoms, centers, etc.)? Thank you

Kevin