Purification, crystallization and preliminary X-ray analysis of the effector domain of AlsR, an LysR-type transcriptional regulator from Bacillus subtilis.

AlsR from Bacillus subtilis, a member of the LysR-type transcriptional regulator (LTTR) family, regulates the transcription of the alsSD operon encoding enzymes involved in acetoin biosynthesis. LTTRs represent the largest known family of transcriptional regulators in bacteria. In this study, AlsR82-302S100A, representing the effector domain, was produced in Escherichia coli, purified and crystallized using the sitting-drop vapour-diffusion method in the presence of 2.1 M DL-malic acid pH 7.0 at 293 K. The crystals belonged to space group C2, with unit-cell parameters a = 142.91, b = 74.96, c = 94.39 Å, β = 110.543°. X-ray data extending to a resolution of 2.6 Å were collected.