Chris, We observed electron density for an intermolecular disulfide bond in a protein that appears to be monomeric in solution.
See Cys166 in 4DSG or 4DSH. https://www.ncbi.nlm.nih.gov/pubmed/22646091 Jack John J. Tanner Professor of Biochemistry and Chemistry Associate Chair of Biochemistry Department of Biochemistry University of Missouri 117 Schweitzer Hall 503 S College Avenue Columbia, MO 65211 Phone: 573-884-1280 Email: tanne...@missouri.edu<mailto:tanne...@missouri.edu> http://faculty.missouri.edu/~tannerjj/tannergroup/tanner.html Lab: Schlundt Annex rooms 3,6,9, 203B, 203C Office: Schlundt Annex 203A On Jan 21, 2020, at 11:55 AM, Chris Fage <fage...@gmail.com<mailto:fage...@gmail.com>> wrote: Dear CCP4BB Users, I've recently solved the ~2.2 angstrom structure of a protein. In my electron density there are unusual monomer-monomer interfaces involving pairs of His and Cys residues (see https://ibb.co/wdWBcdk). Note the positive Fo-Fc density between the four side chains. As there is not adequate space for a water molecule or metal ion, perhaps the Cys residues are partially tied up disulfide bonds? However, the protein looks to be fully monomeric based on LC-MS measurements. Has anyone else observed crystal-driven formation of disulfide bridges? Aside from this region, there is no extensive interface between momoners, and PDBePISA suggests a monomeric state. Thanks in advance for any advice! Best wishes, Chris ________________________________ To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=CCP4BB&A=1 ######################################################################## To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=CCP4BB&A=1