Crystallization and preliminary crystallographic analysis of the kinase-recruitment domain of the PP2C-type phosphatase RsbU.

The general stress response of Bacillus subtilis provides a protective resistance to a variety of pressures. The key molecule is a subunit of RNA polymerase, sigma(B), which confers promoter specificity and is regulated by two signalling modules. Each module comprises protein kinases and phosphatases and 'switch' protein substrates for the kinase and phosphatase. The phosphorylation state of the switch molecules indirectly controls the activity of sigma(B). The binding of the kinase RsbT to the phosphatase RsbU stimulates its enzymatic activity towards its substrate, phosphorylated RsbV. To understand how these enzymes interact, thus regulating transcription, crystallization of the kinase-recruitment domain of RsbU in a form suitable for high-resolution structure determination is reported.