Crystallization and X-ray studies of the DNA-binding domain of OmpR protein, a positive regulator involved in activation of osmoregulatory genes in Escherichia coli.

The OmpR protein of Escherichia coli is a positive regulator involved in the activation of expression of ompC and ompF genes encoding the major outer membrane protein OmpC and OmpF, respectively. The C-terminal half domain of OmpR (OmpR-C), which is responsible for DNA-binding, has been crystallized using the hanging drop vapour diffusion method. X-ray studies show that the crystals belong to the trigonal space group P3(1)21 (or P3(2)21) with a = b = 60.4 A, c = 58.8 A and gamma = 120 degrees. The asymmetric unit contains one molecule. The crystals diffract to at least 3 A resolution and are suitable for X-ray structure analysis.