Hello Experts,
I am trying to solve structure of a protein (213 a.a) complexed with a peptide (14mer) using molecular replacement method. The complex crystals are diffracted around 1.7 A and data is processed in p3(2)21 space group. The structure was solved using apo protein with good LLG -3148 and TFZ score- 49. The modeis refined in phenix the Rfactor -26.0 and Rfree is 28.0. I have added ligand molecule in positive density and also added water molecules (200), followed TLS refinement but still the Rfactor not came down much ( Rfactor-21.53 and Rfree-25.44). There no outliers in Ramachandran plot and most of the residues (97.21) are favored region. Can you please suggest, what can be done to reduce the Rfree? Thanking you in advance. DCB -- Mr.Dilip C. Badgujar, Senior Research Fellow, ACTREC, Tata Memorial Center, Sector-22, Kharghar, Navi Mumbai. Pin-410210
