Overexpression, purification, crystallization and preliminary X-ray diffraction analysis of the C-terminal domain of Ss-LrpB, a transcription regulator from Sulfolobus solfataricus.

Ss-LrpB from Sulfolobus solfataricus P2 belongs to the bacterial/archaeal superfamily of Lrp-like (leucine-responsive regulatory protein-like) transcription regulators. The N-terminal DNA-binding domain contains a HTH motif and the C-terminal domain contains an alphabeta-sandwich (betaalphabetabetaalphabeta fold). The C-terminal domain was overexpressed in Escherichia coli, purified and crystallized using the hanging-drop vapour-diffusion method. The crystals belong to space group P2(1)2(1)2, with unit-cell parameters a = 59.35, b = 74.86, c = 38.08 A and a data set was collected to 2.0 A resolution. Structure determination using a selenomethionine derivative is under way.