Overproduction, crystallization, and preliminary X‐ray diffraction studies of the major cold shock protein from Bacillus subtilis, CspB

Abstract

The major co ld shock protein form Bacillus subtilis (CspB) was voerexressed using the bacteriophage T7 RNA polymerase/promotor system and purified to apparent homogeneity from recombinant Escherichia coli cells. CspB was crystallized in two different forms using vapor diffusion methods. The first crystal form obtained with ammonium sulfate as precipitant belongs to the trigonal crystal system, space group P3₁21 (P3₂21) with unit cell dimensions a = b = 59.1 Å and c = 46.4 Å. The second crystal form is tetragonal, space group P4₁2₁2 (P4₃2₁2) with unit cell dimensionsa = b = 56.9 Å and c = 53.0 Å. These crystals grow with polyethylene glycol 4000 as precipitant.