Hi Jin, Could it be the wrong amino acid in the sequence? Have you sequenced the gene construct that you used? The codon usage for HIS is CAC or CAU, and for TYR is UAC or UAU. -
Cheers, Janet ________________________________________ From: CCP4 bulletin board [ccp...@jiscmail.ac.uk] On Behalf Of Jin H. Park [jinhp...@mail.med.upenn.edu] Sent: 04 September 2010 09:53 To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] Mysterious density Dear CCP4 community, I have solved the structure. But, there seems oddly strong density above histidine residue. What could this density be? The protein was in Tris buffer, with NaCl and DTT, and crystallized in NaSCN with PEG. (electron density in the pictures is at 1.5 sigma) Thanks.