NMR characterization of the NADP(H)-binding domain of Escherichia coli transhydrogenase: sequential assignment and global fold

The soluble NADP(H)-binding domain of Escherichia coli transhydrogenase (18 6 amino acids, 20.4 kDa, rotational correlation time 14 ns) was characteriz ed using MIR techniques. The global fold is similar to that of a classical dinucleotide-binding fold with six parallel beta-strands in a central sheet surrounded by helices and irregular structures, but is lacking both alpha D and alpha E. The substrate is bound in an extended conformation at the C- terminal end of the parallel beta-sheet and our data support the notion of a redox dependent structural rearrangement. (C) 1999 Federation of European Biochemical Societies.