Overexpression, purification and crystallization of the tetrameric form of SorC sorbitol operon regulator

The sorbitol operon regulator (SorC) regulates the metabolism of L-sorbose in Klebsiella pneumonia. SorC was overexpressed in Escherichia coli and purified, and crystals were obtained of a tetrameric form. A single crystal showed X-ray diffraction to 3.20 Å. The crystal belongs to space group P2₁2₁2₁, with unit-cell parameters a = 91.6, b = 113.3, c = 184.1 Å. Analysis of the molecular-replacement solution indicates the presence of four SorC molecules in the asymmetric unit.