Hi Uma, I wish you would have shown negative densities on Fo-Fc maps as well. You protein (and the "template" one) may end up being a classical case to demonstrate how radiation-induced changes may lead to undesirable interpretations. Especially because it is a Cys and because it is in the active site. Cheers, Nukri
Ruslan Sanishvili (Nukri), Ph.D. GM/CA-CAT Biosciences Division, ANL 9700 S. Cass Ave. Argonne, IL 60439 Tel: (630)252-0665 Fax: (630)252-0667 [email protected] ________________________________ From: CCP4 bulletin board [mailto:[email protected]] On Behalf Of Uma Ratu Sent: Friday, May 04, 2012 10:00 AM To: [email protected] Subject: [ccp4bb] CSX Dear All: My protein has a key cysteine residue involved in catalytic activity. The template structure used for the modeling has the same key cysteine. In the template structure, this key cysteine residue is assigned as CSX based on the observation from its electronic density. I compared the electron density from the template as well as my model. I can't tell if the cysteine in my model is oxidized or not. The ones from the template also looks different from each other, although both assigned as CSX. I have the snapshots of these cysteines attached. The ones from my model named as "M-", and the ones from the template named as "T-". Plus, how to change the residue label from Cys to CSX if the cystein is oxidized? In coot, I could not find such function. Thank you very much for your advice Uma
