I've actually seen something like this on disulfides (or at least I think so, I havent seen your density obviously), turned out it was model bias in MR, if I used a different template for MR the feature went away. This was high resolution stuff (~1.0 Å).
Flip -----Original Message----- From: CCP4 bulletin board [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Tuesday, April 10, 2007 20:44 To: [EMAIL PROTECTED] Subject: Re: [ccp4bb] oxidised cys Hi Stefano, How certain are you that this link is truly what you think it is? If I understand what you're saying - you want to create a (thioperoxythio) link - this chemistry should be hideously unstable. Can you explain this using disorder, or perhaps the residual density is a symmetry artifact? Regards, Artem > Dear all > in my structure I think I can see an oxidised Cys in cys-SO. Refining > cys-SO > I observe a residual density between the oxigen of one oxidised cys and > the > one of the other molecule in AU. > I'd like to try to refine it as cys-SO-OS-cys. I didn't find an example of > it in the pdb database. Could anyone tell me whether there are other > cases? > I guess I just didn't find them. > Second question: > How could I "explain" to refmac that there is the OO bond? > I tried to write a line similar to the one for SSBOND in the pdb header > OOBOND 1 CEA A 42 CEA D 42 > but refmac couldn't care less... > > thanks in advance > > Stefano > > _________________________________________________________________ > Express yourself instantly with MSN Messenger! Download today it's FREE! > http://messenger.msn.click-url.com/go/onm00200471ave/direct/01/ >
