The biosynthesis of 6,7-dimethyl-8-(1-D-ribityl)-lumazine from 5-amino-6-(5-phosphoribitylamino)uracil and D-ribose 5-phosphate in KEGG and in BioMeta. Reaction entry R04457 from KEGG is shown with the problems indicated, including the product being shown on the left-hand side. The carbon and phosphorus imbalance causes the reaction to be unbalanced in oxygen and hydrogen as well. In BioMeta three reaction steps have been added to correctly represent this chemistry. Note that the reaction from D-ribose 5-phosphate to D-ribulose 5-phosphate (the reactant of MR005453) was already present in the database.