- The crystallographic structure of a human dihydropteridine reductase NADH binary complex expressed in Escherichia coli by a cDNA constructed from its rat homologue. Su, Y., Varughese, K.I., Xuong, N.H., Bray, T.L., Roche, D.J., Whiteley, J.M. J. Biol. Chem. (1993)