As long as you have processed your data to keep I+ and I- meged separately - default for all CCP4 style data processing it is trivial to do an anom diff map - see CCP4I2 refinement or other procedures. - Usually the S show up in this map and give you a scale for peak height. Then IF you have a peak in an interesting place, and IF you know the wave length, and IF you know something about what might be there, it should be possible to make a good guess. Fe??? Zn?? etc .
On Tue, 21 Jan 2020 at 21:23, Tanner, John J. <tanne...@missouri.edu> wrote: > 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 > 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> 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 > ######################################################################## To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=CCP4BB&A=1
