Hi Christian
One guess would be one of the possible post translational
modifications seen for Lysine. acetylation or a triple methylation.
However propionylations and butyrylations have also been observed on
lysine.
It looks like you could build in waters, you may want to leave this
lysine till later and see if more clear density show up.
good luck
Preben
On 29/06/2010, at 21.52, Christian Biertuempfel wrote:
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
_______________________________________________________________________
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Jens Preben Morth, Ph.D
Aarhus University
Department of Molecular Biology
Gustav Wieds Vej 10 C
DK - 8000 Aarhus C
Tel. +45 8942 5257, Fax. +45 8612 3178
j...@mb.au.dk
website: http://person.au.dk/en/j...@mb.au.dk
