> On 26/04/2020 16:21, Abhishek Anan wrote: > > Dear all, > > > > I have a peptide crystal structure at 0.97 Å that contains two surface > > exposed Methionine. The CE atoms of both MET have a suspiciously high > > b-factor >40 and a positive density. In addition, the sulfur atom SD > > has a large negative density (b-factor ~23). > > > > I initially suspected that the MET may have oxidized to MET-sulfoxide > > and tried to model only the MET-sulfoxide. This again resulted in > > negative density. > > > > I think that the peptides might be partly oxidized which brings me to > > my question. Is there a way to model both MET and MET-sulfoxide into > > the density much like alternate conformation with options to refine > > their respective occupancies. > > > Yes. This is called micro-heterogeneity > > And is documented here: > > https://www.wwpdb.org/documentation/procedure > > That should "just work" if you then give the model to refmac. > > FWIW, Coot is, AFAIR, not 100% happy with such models. Neither is Refmac ☹
Cheers, Robbie > > Paul. > > ################################################################ > ######## > > 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
