N4-hydroxymethyl-L-asparagine 144.053497314453125 144.1300048828125 30.010564804077148438 30.030000686645507812 N(gamma)-hydroxymethylasparagine MOD:00241 N C 1 H 2 O 1 PSI-MOD none Hydroxymethyl hydroxymethyl C 5 H 8 N 2 O 3 (2S)-2-amino-4-[(hydroxymethyl)amino]-4-oxobutanoic acid artifact A protein modification that effectively converts an L-asparagine residue to N4-hydroxymethyl-L-asparagine. beta-hydroxymethylasparagine N4-methyl-L-asparagine, see MOD:0079, was found at a homologous position of the same protein in a closely related species. Since the peptide containing this modification was obtained by enzymatic cleavage, not cyanogen bromide cleavage, it could have experienced oxidation of the following methionine residue, leading to the erroneous attribution of a mass of 29 for the modification rather than 14. comment: This is a deprecated entry in RESID. It probably does not occur naturally [JSG]. N4-hydroxymethylasparagine 2-amino-N4-hydroxymethylbutanediamic acid N4-hydroxymethyl-L-asparagine modified L-asparagine residue