Sedelnikova S E, Burke J, Buckley P A, Rice D W, Jackson J B, Cotton N P, Grimley R L, Baker P J
The Krebs Institute, Department of Molecular Biology and Biotechnology, University of Sheffield, Western Bank, Sheffield S10 2TN, England.
Acta Crystallogr D Biol Crystallogr. 2000 Sep;56(Pt 9):1170-2. doi: 10.1107/s0907444900008179.
Nicotinamide nucleotide transhydrogenase couples the exchange of a hydride-ion equivalent between NAD(H) and NADP(H) to the translocation of protons across an energy-transducing membrane. Peripheral components of 380 and 200 residues bind NAD(H) (dI) and NADP(H) (dIII), respectively, while a third component forms a membrane-spanning region (dII). The NAD(H)-binding component dI of Rhodospirillum rubrum transhydrogenase has been crystallized in a form which diffracts to beyond 3.0 A resolution and is in space group P2 or P2(1), with unit-cell parameters a = 69.3, b = 117.8, c = 106.6 A, beta = 107.2 degrees and two dimers in the asymmetric unit. The sequence of the dI component is similar to that of alanine dehydrogenase. A full structure determination will lead to important information on the mode of action of this proton pump and will permit the comparison of the structure-function relationships of dI with those of alanine dehydrogenase.
