Preparation, Crystallization and Preliminary X-Ray Analysis of Threonine Synthase from Streptococcus mutans

The thrC gene of Streptococcus mutans encodes threonine synthase, which is a potential target for drug design. To study the structure and function of the enzyme, the thrC gene was amplified from Streptococcus mutans genomic DNA and cloned into the expression vector pET28α. The protein 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. The crystal diffracted to 2.5 Å and belonged to space group P31 or P32, with unit cell parameters a=b=60.39 Å, c=118.62 Å.