Crystallization and preliminary crystallographic analysis of the NAD(H)-binding domain of Escherichia coli transhydrogenase

Transhydrogenase is a proton-pumping membrane protein that is required for the cellular regeneration of NADPH. The NAD(H)-binding domain (domain I) of transhydrogenase from Escherichia coli was crystallized using the hanging-drop vapour-diffusion technique at room temperature. The crystals, which were grown from PEG 4000 and ammonium acetate in citrate buffer, belong to the triclinic space group P1, with unit-cell parameters a = 38.8, b = 66.8, c = 76.4 Å, α = 67.5, β = 80.8, γ = 81.5°. X-ray diffraction data were collected to 1.9 Å resolution using synchrotron radiation. The crystals contain one dimer of transhydrogenase domain I per asymmetric unit.