Crystallization and preliminary X-ray diffraction analysis of the NAD-dependent non-­phosphorylating GAPDH of the hyperthermophilic archaeon Thermoproteus tenax

Recombinant non-phosphorylating NAD⁺-dependent glyceraldehyde-3-phosphate dehydrogenase (GAPN) of the hyperthermophilic crenarchaeote Thermoproteus tenax has been overexpressed, purified and crystallized using the hanging-drop vapour-diffusion technique. Crystals of different habits were obtained from several precipitant solutions (salts and polyethylene glycols). Preliminary X-ray analysis was performed with crystals grown in ammonium formate, which belonged to the primitive hexagonal space group P622, and had unit-cell parameters a = b = 184.8, c = 133.0 Å, γ = 120°. Assuming a molecular weight of 55 kDa, a Matthews parameter of 3.3 ų Da⁻¹ is calculated assuming two molecules per asymmetric unit. The diffraction limit of these crystals is 2.5 Å resolution.