Hi Ibrahim,
I'm not 100% sure why you want to rainbow the highlighted part of your structure, rather than use a single color, or color the rest of the structure dark gray, or make the rest of the structure semi-transparent, or many other possible highlighting schemes.
Anyway, there's no way to do it without resorting to (simple) Python.  Put the following in a file that ends in ".py":

import chimera
residues = chimera.selection.currentResidues()
residues.sort()
for i, r in enumerate(residues):
r.highlightNum = i+1

Then select the residues you want highlighted in Chimera.  Run the Python script by opening it with the "open" command or with the File->Open dialog.  Then run this Chimera command:

rangecolor highlightNum,r min blue mid white max red sel

--Eric

                        Eric Pettersen

                        UCSF Computer Graphics Lab

                        http://www.cgl.ucsf.edu



On Nov 9, 2009, at 11:14 AM, Ibrahim Moustafa wrote:

Dear Chimera team,

  I wonder if there is a way to color a certain range of residues using rainbow.
I tried to use the rainbow command with atom_spec but it applied for the whole chain.

 What I want to do is to color part of the structure as a rainbow (from blue-white-red) with an increasing order of residues number.
I just wanted to highlight a region of conformational change so the eye can follow which part of the structure has changed dramatically.


  Thanks in advance for your help.

  Ibrahim

--

Ibrahim M. Moustafa, Ph.D.
Biochemistry and Molecular Biology Dept.
201 Althouse Lab., University Park,
Pennsylvania State University
PA 16802

Tel. (814) 863-8703
Fax (814) 865-7927

 
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