Re: [phenixbb] Real space refine of long side chains

Hi, We have addressed exactly this problem by writing a script, in which B-factors are refined first and only then real-space refinement happens. This allows disordered side-chains to acquire high B-factors and so they are not pulled into backbone anymore. This cycle is repeated twice to achieve convergence. Parameters for B-factor refinement (ADP restrains) were optimized to account for consistent lack of density for acidic side chains in cryoEM. It is described in: https://www.ncbi.nlm.nih.gov/pubmed/31492636 If needed, I can send a script. Best Leonid -- Prof. Leonid Sazanov FRS IST Austria Am Campus 1 A-3400 Klosterneuburg Austria Phone: +43 2243 9000 3026 E-mail: [email protected] Date: Mon, 25 Nov 2019 19:11:16 +0000 From: Luca Pellegrini To: PHENIX user mailing list Subject: [phenixbb] Real space refine of long side chains Message-ID: <[email protected]> Content-Type: text/plain; charset=us-ascii I have noticed that real-space refinement in cryoEM maps has a tendency to pull long disordered side chains (Lys, Glu etc) back towards main chain density, resulting in unrealistic hairpin-like bent conformations. Is there a way to counter or moderate this behaviour? It would save me from having to manually straighten them all out again afterwards... Best wishes, Luca Luca Pellegrini, PhD Department of Biochemistry University of Cambridge Cambridge CB2 1GA United Kingdom [email protected] tel.: 0044 1223 760469 https://www.bioc.cam.ac.uk/pellegrini-group/pellegrini-group @PellegriniLab