From: Ashar Malik (asharjm_at_gmail.com)
Date: Thu Apr 21 2016 - 13:28:42 CDT

My guess is that "backbone" works for both proteins and DNA. DNA has a
phosphate backbone which would explain why the 3 extra atoms you have have
"P" in them.
On Apr 22, 2016 4:52 AM, "Stefan Doerr" <stefdoerr_at_gmail.com> wrote:

> Hi, I was trying to remove a engineered residue from a protein when I fell
> upon weird behaviour in atomselect.
> http://www.rcsb.org/pdb/explore.do?structureId=5HX8
>
> If you try "resname PTR and backbone" you will notice that this leaves
> behind 3 atoms, P, OP1 and OP2 which are obviously not backbone.
>
> What is the reason for that?
>
> Greetings,
> Stefan
>