From: John Stone (johns_at_ks.uiuc.edu)
Date: Mon Oct 31 2011 - 14:39:13 CDT

I think you need to change it to something like this:
  "(proteinback or nucleicback) and not within 12 of resname X"

It is often important to use parenthesis so the selection parser
interprets the precedence of various selection operations correctly.

Cheers,
  John Stone
  vmd_at_ks.uiuc.edu

On Mon, Oct 31, 2011 at 08:39:43PM +0200, matziast_at_med.uth.gr wrote:
> Hi,
> I want to select only the protein backbone and the nucleic backbone and not
> within 12 or resname X.
> For that reason I type "proteinback or nucleicback and not within 12 of resname
> X"
> but the final selection included all proteins and backbone. Why?
> I would appreciate if anyone could help me.
> Thank you in advance.
>

-- 
NIH Resource for Macromolecular Modeling and Bioinformatics
Beckman Institute for Advanced Science and Technology
University of Illinois, 405 N. Mathews Ave, Urbana, IL 61801
http://www.ks.uiuc.edu/~johns/           Phone: 217-244-3349
http://www.ks.uiuc.edu/Research/vmd/       Fax: 217-244-6078