Dear Sayan, It's a little hard to see from the images, but there seems to be continuous density to the aspartate indicating a covalent adduct. Perhaps it would be best to extract a crystal and run it through mass spec to get an exact mass on the adduct (and so its chemical formula)? Others who have done this might comment on whether that is a good idea! I dare say that we can speculate; but if it is important to the story of your paper, you will need additional evidence to support whatever you model into this density.
Kind regards, Nic Harmer Prof. Nicholas Harmer Associate Professor in Structural Biochemistry University of Exeter Living Systems Institute Stocker Road Exeter EX4 4QD UK From: CCP4 bulletin board <CCP4BB@JISCMAIL.AC.UK> On Behalf Of Sayan Saha Sent: 30 June 2022 08:03 To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] Unidentified electron density CAUTION: This email originated from outside of the organisation. Do not click links or open attachments unless you recognise the sender and know the content is safe. Dear All, I am trying to refine a protein structure. I observed an additional electron density (Figures attached) connected to the aspartate residue. Any suggestion in this regard would be appreciated. With best regards, Sayan Saha. ________________________________ To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1<https://eur03.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.jiscmail.ac.uk%2Fcgi-bin%2FWA-JISC.exe%3FSUBED1%3DCCP4BB%26A%3D1&data=05%7C01%7CN.J.Harmer%40exeter.ac.uk%7Ce8f2cbe242494ab2f49b08da5a681790%7C912a5d77fb984eeeaf321334d8f04a53%7C0%7C0%7C637921700366519564%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000%7C%7C%7C&sdata=ofAGA%2BVT%2BnE7bUfHP1pANsDksXNAXftvN1OHni%2FwPf8%3D&reserved=0> ######################################################################## 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/
