Re: software to convert XYZ format to PDB ?



 Michel Petitjean wrote:
 
 To: chemistry<<at>>ccl.net
 Subject: CCL:software to convert  XYZ format to PDB ?
 Konrad Hinsen <hinsen<<at>>cnrs-orleans.fr> wrote:
 
 If I had to do this (fortunately I don't), I'd first identify the
 
peptide planes as patterns of pairwise distances (they are quite rigid). I'd then identify the sidechains atom by atom starting from the C-alphas, again by distance criteria. Not a trivial task, but not an impossible one either.
 Sure... if you have the side chains ! (were not indicated in the example)
 It needs other assumptions: true residues, no HETATM, lexicographical
 ordering coherent with the PDB conventions...
 
 There are programs (such as ARP/wARP) which start with NO atom information, not
 even coordinates, and can correctly build a protein structure based on an
 electron density map using pattern recognition techniques.  The ambiguities
 there, such as ASP vs. ASN, are not present when you know the elements, as we do
 here.  ARP/wARP is also gaining ligand building capabilities and already handles
 water molecules.
 ARP is part of CCP4 so you get source code with it.
 http://www.embl-hamburg.de/ARP/
 Of course if you have any unexplained data (whether electron density or known
 atom positions) that do not fit the pattern of an amino acid, you can just leave
 them alone and inform the user.
 --
 Eric Bennett, Center for Drug Design, U of Minnesota