Dear All,<div>I have a theoretical/practical question about omit maps and refinement.<br><div>I am completing the refinement (in Phenix) of a protein-ligand complex at 1.3A resolution. I solved it by MR and automatic rebuilding of the protein alone first then built in the ligand. Rfree and Rfac are 19.4%/18.2% after TLS and water-picking in Phenix. The model includes everything protein, water, ligand and some ions.</div>
<div>However I have some slight doubts one region in my ligand. </div><div>What would be the best map, less biased, to look at this &quot;very late&quot; stage of the refinement. Are  composite or systematic SA omit map useful options at this stage ?</div>
<div><br></div><div>Thanks a lot in advance</div><div><br></div><div><br></div><div>Pascal F. Egea, PhD<br>Assistant Professor<br>UCLA, David Geffen School of Medicine<br>Department of Biological Chemistry<br>314 Biomedical Sciences Research Building <br>
office (310)-825-1013<br>lab 	 (310)-825-8722<br>email	 <a href="mailto:pegea@mednet.ucla.edu">pegea@mednet.ucla.edu</a><br><br>
</div></div>