Crystallization and preliminary X-ray diffraction studies on the N-utilizing substance-B (NusB) from Mycobacterium tuberculosis

N-utilizing substance B (NusB) is a protein which forms part of a complex assembly in transcriptional antitermination in Mycobacterium tuberculosis. It forms a heterodimer with the product of the NusE gene (identical to the ribosomal protein S10) and mediates the process of transcriptional antitermination by forming the core complex with the nut site of the ribosomal RNA along with other protein factors. NusB has been cloned and overexpressed in Escherichia coli and crystallized using the hanging-drop vapour-diffusion method. The space group is P2₁2₁2₁, with unit-cell parameters a = 46.6, b = 64.2, c = 90.1 Å. A native data set complete to 1.6 Å resolution has been collected from a single crystal.