label: (6R)-5,10-methylene-5,6,7,8-tetrahydrofolate + D-serine + H2O => alpha-(hydroxymethyl)serine + (6S)-5,6,7,8-tetrahydrofolate
label_lc: (6r)-5,10-methylene-5,6,7,8-tetrahydrofolate + d-serine + h2o => alpha-(hydroxymethyl)serine + (6s)-5,6,7,8-tetrahydrofolate