My best guess would be acetylation/propionylation with the oxygen pointing into the top small green density.
cheers Ajit B. ----- Original Message ----- From: Christian Biertuempfel <[email protected]> Date: Tuesday, June 29, 2010 2:54 pm Subject: [ccp4bb] density quiz To: [email protected] > Dear all, > Does anyone have an idea what this density at a lysine residue could be? > The structure is a protein-DNA complex and I suspect that something > left-over from the DNA synthesis reacted with the amino group even > though the DNA substrate was purified. > > christian > > p.s. The protein has seen the following substances during purification > and crystallization: Leupeptin, Pepstatin, AEBSF, MES, Tris, HEPES, DTT, > EDTA, imidazole, glycerol, PEG 2K-MME, Mg2+, Na+, K+, Ca2+, Cl-. > > > _______________________________________________________________________ > > Dr. Christian Biertümpfel > Laboratory of Molecular Biology > > NIDDK/National Institutes of Health phone: +1 301 402 4647 > 9000 Rockville Pike, Bldg. 5, Rm. B1-03 fax: +1 301 496 0201 > Bethesda, MD 20892-0580 > USA > _______________________________________________________________________
