Hello All, I have run into something odd. In working on a structure for one of the groups I work with regularly, on one of the cystine residues I have a very large positive density peak at the sulfur position. The B value is approximately 4 times the other values in the residue and on other cystine residues. The overall structure has 2 molecules in the asymmetric unit and the corresponding cystine on the other monomer is behaving as I would expect. There are no disulfides in the structure.
The data were collected on 9-2 at SSRL and all three of the data sets we collected show the same thing, all data go to about 2.2 angstroms. We are trying to determine the ligand binding in the molecule but this cystine is not involved in ligand binding. In house and other synchrotron data from previous protein preps and data collection runs of the same molecule grown in very similar condition and crystallized in the same space group have the residue behaving normally. I am open to any ideas as to what may be going on as I am rather puzzled by this. Thanks for any input, Len Thomas Leonard Thomas, Ph.D. Biomolecular Structure Core, Director Oklahoma COBRE in Structural Biology Price Family Foundation Institute of Structural Biology University of Oklahoma Department of Chemistry and Biochemistry 101 Stephenson Parkway Norman, OK 73019-5251 Office: (405)325-1126 lmtho...@ou.edu<mailto:lmtho...@ou.edu> http://www.ou.edu/structuralbiology/cobre-core-facilities/mcl ######################################################################## To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 This message was issued to members of www.jiscmail.ac.uk/CCP4BB, a mailing list hosted by www.jiscmail.ac.uk, terms & conditions are available at https://www.jiscmail.ac.uk/policyandsecurity/
