Protein Preparation, Crystallization and Preliminary X-Ray Crystallographic Analysis of N-Acetylglutamate Kinase from Streptococcus mutans

The N-acetylglutamate kinase from Streptococcus mutans was expressed in Escherichia coli in soluble form and purified to homogeneity. Crystals suitable for X-ray diffraction were obtained by hanging-drop vapor diffusion method and diffracted to 2.06 Å. The crystal belonged to space group P21212, with unit cell parameters a = 57.19 Å, b =94.76 Å, c =47.58 Å. The gel filtration and initial phasing results showed that the enzyme exists as a monomer, which is different from previously reported N-acetylglutamate kinases.