... were of two types, either with the two-domain architecture of the RibG protein of Bacil-lus subtilis or the RibD protein of E. coli, respectively[18–20], or the single-domain type of 2,5-diamino-6-ribitylamino-4(3H)-pyrimidinone ... reductase domain islocated at the N-terminus and the predicted deaminaseat the C-terminus of the bifunctional protein. In plants, orthologues of pyrimidine reductases of the riboflavin pathway ... pyrimi-dine carbon atom shows two singlet signals in the case of the substrate, which reflect the two anomers. In contrast, the position 2 pyrimidine carbon of the product shows only one singlet, as the...