Crystallization and preliminary X-ray diffraction studies of 6-phosphogluconate dehydrogenase from Lactococcus lactis

6-Phosphogluconate dehydrogenase is one of the seven enzymes involved in the pentose phosphate pathway. Crystals of a mammalian and a protozoan enzyme have been obtained previously and structures determined. It is reported here that a bacterial 6-phosphogluconate dehydrogenase, from Lactococcus lactis, has been purified and used in crystallization trials. Large prisms suitable for a detailed structural analysis have been obtained and characterized as orthorhombic, space group F222, with a = 70.4, b = 105.7, c = 474.6 Å. Diffraction has been observed to 2.2 Å resolution using synchrotron radiation. Structural analysis, in combination with ongoing biochemical characterization, will assist the elucidation of the structure–activity relationships of this enzyme.