A new tyrosine phosphorylation mechanism involved in signal transduction in Bacillus subtilis

J Mol Microbiol Biotechnol. 2005;9(3-4):182-8. doi: 10.1159/000089646.


A new kind of prokaryotic protein tyrosine kinase was recently discovered, utilizing a guanidino-phosphotransferase domain for its kinase activity. Guanidino kinase domains originate from eukaryotic phosphagen kinases, a family of phosphoryl transfer enzymes with no homology to the serine/threonine and tyrosine kinase superfamily. Nevertheless, this kinase, McsB, exhibits the main structural and functional properties of prokaryotic tyrosine kinases. Tyrosine phosphorylation in bacteria is predominantly described to be involved in the regulation of exopolysaccharide synthesis and is therefore required for biofilm formation and virulence. McsB on the other hand modulates together with its activator protein, McsA, the activity of the repressor of the class III heat shock genes in B. subtilis. The analogy of the kinase mechanism of McsB to tyrosine kinases implicates that tyrosine kinases may harbor various and independently evolved domains for ATP-binding/hydrolysis and the transfer of the gamma-phosphate of ATP onto tyrosine residues.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Adaptation, Physiological
  • Bacillus subtilis / enzymology*
  • Bacillus subtilis / metabolism
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / metabolism*
  • Heat-Shock Proteins / metabolism
  • Models, Biological
  • Phosphoprotein Phosphatases / metabolism
  • Phosphorylation
  • Phosphotyrosine / metabolism
  • Protein Kinases / chemistry
  • Protein Kinases / metabolism*
  • Protein Processing, Post-Translational
  • Protein-Tyrosine Kinases / metabolism
  • Signal Transduction*


  • Bacterial Proteins
  • ClpC protein, Bacteria
  • Heat-Shock Proteins
  • McsA protein, Bacillus subtilis
  • Phosphotyrosine
  • Protein Kinases
  • McsB protein, Bacillus subtilis
  • Protein-Tyrosine Kinases
  • Phosphoprotein Phosphatases