O-phospho-L-serine (2S)-2-amino-3-(phosphonooxy)propanoic acid 166.99835205078125 167.05999755859375 2-amino-3-hydroxypropanoic acid 3-phosphate 2-azanyl-3-(phosphonooxy)propanoic acid 79.96633148193359375 79.98000335693359375 A protein modification that effectively converts an L-serine residue to O-phospho-L-serine. ACT_SITE Phosphoserine intermediate C 0 H 1 N 0 O 3 P 1 C 3 H 6 N 1 O 5 P 1 MOD:00046 MOD_RES Phosphoserine O-phospho-L-serine O-phosphonoserine O-phosphorylated L-serine O3-phosphoserine OPSer PSI-MOD Phospho Phospho Seryl Phosphorylation S Unimod:21 natural phosphorylations serine phosphate ester uniprot.ptm:PTM-0253 residues isobaric at 166.98-167.00 Da modified L-serine residue O-phosphorylated residue