Hi Mehdi, I misunderstood your question. I thought you meant the atomspec balloons that temporarily pop up when you put the mouse over the atoms, and the previous instructions apply to those. Your picture shows the regular residue labels. To show a residue label, the residue's ribbon or some of its atoms must be displayed. It is OK for the surface to also be shown, but then the problem is that the surface usually covers up the residue labels so you can't see them. You can make the surface transparent to see the labels inside (see "Actions... Surface... transparency..." in the menu or use the command "surftransparency"). <http://www.cgl.ucsf.edu/chimera/docs/UsersGuide/midas/surftransparency.html

If you are displaying these labels to make a figure, another suggestion is to use 2D Labels. You have to enter the text of a 2D label yourself, but you can move it to any position in the window. 2D Labels are independent of the structure and how it is displayed. <http://www.cgl.ucsf.edu/chimera/docs/ContributedSoftware/2dlabels/2dlabels.h...

Elaine ----- Elaine C. Meng, Ph.D. meng@cgl.ucsf.edu UCSF Computer Graphics Lab and Babbitt Lab Department of Pharmaceutical Chemistry University of California, San Francisco http://www.cgl.ucsf.edu/home/meng/index.html On Dec 7, 2008, at 11:31 AM, Mehdi wrote:

Thank you for your detailed information. I could not still figure out how to label the residues on surface representation. I have attached the figure (for instance) showing the ribbon representation with a few amino acids labeled but if I want to achieve the labeling on the surface the labels,unlike the ribbon, do not appears on it. I also followed the tutorial but the atomspec balloons were not observed on the surface as soon as the ribbon or simple stick representation are hided.Do I have to keep the simple bond or ribbon representation in order to keep the atomspec balloon and labels observable?