Dear all, I am trying to do a phenix.real_space_refine in a CryoEM map at 4.2 Å with a model obtained by MDFF (NAMD, a protein DNA complex) because the resulting structure, despite a good CC and a good molecular geometry has a poor Ramachandran Map. When doing the phenix.real_space_refine, the CC is slightly increased with respect to the starting structure, the Ramachandran is dramatically increased but some part of the model ( in the case, the first three bases pairs a DNA duplex) are strongly distorted because of a lack of density in the corresponding region of the map. For some reason, this does not append with the MDFF method. I was wondering if there is a mean, in phenix.real_space_refine, to exclude a part of the model from being fitted in the map. Indeed, the distortion I observe in the DNA duplex is likely due to the fact that the real_space_refine tries to put the atoms at the extremity of the duplex in the closest density at the price of a strong distortion of the structure. Thank in advance for your suggestions. Best regards. Philippe. ----------------------------------------------- Philippe Cuniasse, PhD/HDR. Institut de Biologie Integrative de la cellule. UMR 9198 CNRS-CEA-Univ Paris Sud Bat 144 CE-Saclay 91191 Gif-sur-Yvette Cedex France Tel: (33) 1 69 08 56 35 Fax: (33) 1 69 08 47 12 Email: [email protected]mailto:[email protected] Web: http://biodev.cea.fr/rasmot3d/ [signature_3454313285][signature_3433042689][signature_3416814468] -----------------------------------------------
