I also have seen similar. I was thinking it was potentially some kind of radiation damage? Is there a good paper which examines what chemistries are seen in rad damage?
Jacob On Thu, Nov 17, 2011 at 5:39 AM, Eleanor Dodson <c...@ysbl.york.ac.uk> wrote: > Yes - I have seen something similar at a lower resolution, but very ugly! I > tried to model it as a solvent molecule - possible but not too convincing.. > > Cl should give an anomalous signal - try a DANO map and see what it shows.. > Eleanor > > > On 11/17/2011 11:09 AM, Dean Derbyshire wrote: >> >> Hi all, >> Has anyone observed 'odd' arginine residues, missing the NH1 atom; and >> possibly related.. very close Chlorine-arginine (NH1 again) distances. >> >> I have a 1.3Å structure and am having trouble getting my head around some >> very odd density features. >> >> I have 2 molecules in the assym. with the equivalent arg residues showing >> the same odd feature. >> Seems to be a chlorine binding site - typical mix of hydrophobic and >> proton rich side chains - but, the NH1 of the particular arginine residue >> concerned (as I say in both NCS copies) seems to have only 50% occupancy and >> the chlorine appears to have a 2nd distinct position closer to the arginine, >> such that if the NH1 atom were present it would be only 2Å away! >> >> ? >> >> Cheers in advance >> >> Dean >> >> >> > -- ******************************************* Jacob Pearson Keller Northwestern University Medical Scientist Training Program email: j-kell...@northwestern.edu *******************************************
