I'm trying to get a translation matrix for two different crystal structures of ribisomal subunits. I've been trying to use the "measure rotation" command but I can only get it to display the following message "rotation angle is near zero (0 degrees)". I was wondering whether the command might be failing due to the fact that the ribosome contains numerous chains, or perhaps because the command does not deal with RNA. At any rate, how would one go about obtaining a translation matrix that can be applied to any model?