part of part of has input has input has output has output process reaction 2-hydroxy-3-oxobutyl phosphate + 5-amino-6-(D-ribitylamino)uracil = 6,7-dimethyl-8-(1-D-ribityl)lumazine + 2 H(2)O + phosphate 1 1 1 1 1 1 UPa:UCR04457 METACYC:LUMAZINESYN-RXN reaction RHEA:26155 KEGG:R04457 riboflavin from 2-hydroxy-3-oxobutyl phosphate and 5-amino-6-(D-ribitylamino)uracil: step 1/2 H(2)O phosphate 6,7-dimethyl-8-(1-D-ribityl)lumazine 5-amino-6-(D-ribitylamino)uracil 2-hydroxy-3-oxobutyl phosphate