Hi,
 
I am trying to make an SA-omit Fo-Fc map for a sugar ligand (chain B) bound to protein (structure solved by MR), without doing any rebuilding of protein or ligand – just calculate an Fo-Fc map that I can load into PyMol.
So far I used the AutoBuild – Create omit map module with these settings :
 
- input files : model (protein+ligand+waters), data (.mtz), restraints for sugar ligand (.cif)
- omit map type : simulated annealing
- omit region : omit selection
- omit map options : keep input waters,  omit chain list : omit_chain_list chainB
 
However, the ligand gets modified even though I use “omit_chain_list chainB”.
What are the parameters to set to keep the model (protein, ligand, waters) from being rebuilt ?
 
Furthermore, what is the procedure to load the SA Fo-Fc omit map into pymol ?
 
Phenix version is 1.6.4-486.
 
Thanks in advance,
Tjaard

Ing. Tjaard Pijning
Research Assistant

Protein Crystallography Group
Nijenborgh 7
9747 AG Groningen
The Netherlands
(31)(0)50 363 43 85