Purification, crystallization and preliminary X-ray diffraction analysis of thermostable nitrile hydratase: research letter

Abstract

Microbial nitrile hydratases are important industrial enzymes that catalyse the conversion of nitriles to the corresponding amides. Bacillus strain RAPc8 nitrile hydratase has recently been cloned and functionally expressed in E. coli. Here, the purification, crystallization and preliminary X-ray diffraction data of this nitrile hydratase are described. The heterotetrameric enzyme was crystallized using the hanging-drop vapour-diffusion method. Crystals produced in the presence of 30% PEG 400, 0.1 M MES (pH 6.5) and 0.1 M magnesium chloride were selected for X-ray diffraction studies. A data set complete to 2.5 Å was collected under cryoconditions at the in-house X-ray source at the University of the Western Cape. The space group was determined to be primitive tetragonal (P41212) with unit cell dimensions a = 106.61 Å, b = 106.61 Å, c=83.23 Å, = = =90°; with one dimer per asymmetric unit. Solution of the three-dimensional structure via molecular replacement is in progress.