O-(phospho-5'-DNA)-L-serine (S)-2-amino-3-(5'-deoxyribonucleic acid phosphonoxy)propanoic acid A protein modification that effectively crosslinks an L-serine residue and the 5'-end of DNA through a phosphodiester bond to form O-(phospho-5'-DNA)-L-serine. ACT_SITE O-(5'-phospho-DNA)-serine intermediate MOD:00251 MOD_RES O-(5'-phospho-DNA)-serine O-(phospho-5'-DNA)-L-serine O3-(phospho-5'-DNA)-L-serine O3-L-serine 5'-DNA phosphodiester PSI-MOD S natural uniprot.ptm:PTM-0226 deoxyribonucleic acid linked residue modified L-serine residue