Crystallization and preliminary diffraction studies of pentaerythritol tetranitrate reductase from Enterobacter cloacae PB2

Pentaerythritol tetranitrate (PETN) reductase of Enterobacter cloacae PB2, a flavoprotein involved in the biodegradation of the explosive PETN, ethylene glycol dinitrate (EGDN) and glycerol trinitrate (GTN), was purified from an overexpressing strain of E. coli and crystallized at 293 K using the sitting-drop vapour-diffusion method. Diffraction data can be seen at 1.8 Å. The primitive orthorhombic cell has a monomer in the asymmetric unit. Preliminary molecular-replacement calculations have been performed using a search model based on Old Yellow enzyme.