Rotate chi2 bond (CB-CG) and have two alternative conformations for the His. Add two water molecules (50% occupancy) each making a H-bond with the NE2 atoms (alternative 1 and 2) of the His.
George From: CCP4 bulletin board [mailto:[email protected]] On Behalf Of SD Y Sent: Saturday, March 08, 2014 7:29 AM To: [email protected] Subject: [ccp4bb] density near Histidine Hi, During refinement, I see a strong density next to His and I have tried metal ions and water but it seems to be different. Known components of crystallization are Tris, NaCl, BME, MgOAc, PEG3350. Its only seen in one chain of AU. Are there any suggestions? Thanks in advance SDY
