A New Mechanism of Phosphoregulation in Signal Transduction Pathways

Histidine protein kinases and serine, threonine, or tyrosine protein kinases play essential roles in signal transduction in prokaryotes and eukaryotes. A third type of protein kinase, an arginine protein kinase, has been identified. McsB of Bacillus subtilis phosphorylates the heat shock transcriptional regulator CtsR and can be regarded as the founding member of arginine protein kinases.