Hi Francesco, If you want detailed information about which atoms contact which, and the distances between them, use the "Find Clashes/Contacts" tool, or its command version "findclash", as discussed in several previous posts: <http://www.cgl.ucsf.edu/pipermail/chimera-users/2008-November/ 003260.html> <http://www.cgl.ucsf.edu/pipermail/chimera-users/2008-October/ 003163.html> <http://www.cgl.ucsf.edu/pipermail/chimera-users/2008-October/ 003183.html> There are links in those posts to the manual pages and a tutorial with an example. Some of those discussions were about finding contacts for a ligand, but the findclash feature is general and can be used on whatever set of atoms/residues you want. Again, you can save results to a file or write them to the Reply Log. Best, Elaine ----- Elaine C. Meng, Ph.D. meng@cgl.ucsf.edu UCSF Computer Graphics Lab (Chimera team) and Babbitt Lab Department of Pharmaceutical Chemistry University of California, San Francisco http://www.cgl.ucsf.edu/home/meng/index.html On Feb 18, 2009, at 10:55 AM, Francesco Pietra wrote:

Hi Elaine:

By doing as indicate in your and my post, only residues (45 residues) for model 0 (the bigger protein) are listed. Then I also commanded:

sel #1:1701-1793 & 0:20,30-40,55 z<5

i.e., inverting the order of the two models. That gave a list of residues (18 residues) for only model 1 (the smaller protein).

Probably all that is useful information. But, is any way (one touch, as above) to get information about which-to-which?

I am not too lazy, I am prepared on the basis of the above two listings, to use the zone command residue per residue, should this be the way.

(the numbers for the above residues are just for a split example; actually I set all residues - even for areas that I knoe are not involved - in the zone command for both proteins)

Thanks francesco