Crystal structure of rat liver dihydropteridine reductase.
Varughese, K.I., Skinner, M.M., Whiteley, J.M., Matthews, D.A., Xuong, N.H.(1992) Proc Natl Acad Sci U S A 89: 6080-6084
- PubMed: 1631094
- DOI: https://doi.org/10.1073/pnas.89.13.6080
- Primary Citation of Related Structures:
1DHR - PubMed Abstract:
The structure of a binary complex of dihydropteridine reductase [DHPR; NAD(P)H:6,7-dihydropteridine oxidoreductase, EC 1.6.99.7] with its cofactor, NADH, has been solved and refined to a final R factor of 15.4% by using 2.3 A diffraction data. DHPR is an alpha/beta protein with a Rossmann-type dinucleotide fold for NADH binding. Insertion of an extra threonine residue in the human enzyme is associated with severe symptoms of a variant form of phenylketonuria and maps to a tightly linked sequence of secondary-structural elements near the dimer interface. Dimerization is mediated by a four-helix bundle motif (two helices from each protomer) having an unusual right-handed twist. DHPR is structurally and mechanistically distinct from dihydrofolate reductase, appearing to more closely resemble certain nicotinamide dinucleotide-requiring flavin-dependent enzymes, such as glutathione reductase.
Organizational Affiliation:
Department of Biology, University of California, San Diego, La Jolla 92093-0317.