Structural changes in the recombinant, NADP(H)-binding component of protontranslocating transhydrogenase revealed by NMR spectroscopy

We have analysed H-1, N-15-HSQC spectra of the recombinant, NADP(H)-binding component of transhydrogenase in. the context of the emerging three dimens ional structure of the protein, Chemical shift perturbations of amino acid residues following replacement of NADP(+) with NADPH mere observed in both the adenosine and nicotinamide parts of the dinucleotide binding site and i n a region which straddles the protein. These observations reflect the stru ctural changes resulting from hydride transfer. The interactions between th e recombinant, NADP(H)binding component and its partner, NAD(H)-binding pro tein, are complicated. Helix B of the recombinant, NADP(H)-binding componen t may play an important role in the binding process. (C) 1999 Federation of European Biochemical Societies.