These authors contributed to this study equally.
The auxiliary protein complex SaePQ activates the phosphatase activity of sensor kinase SaeS in the SaeRS two-component system of Staphylococcus aureus
Article first published online: 27 AUG 2012
© 2012 Blackwell Publishing Ltd
Volume 86, Issue 2, pages 331–348, October 2012
How to Cite
Jeong, D.-W., Cho, H., Jones, M. B., Shatzkes, K., Sun, F., Ji, Q., Liu, Q., Peterson, S. N., He, C. and Bae, T. (2012), The auxiliary protein complex SaePQ activates the phosphatase activity of sensor kinase SaeS in the SaeRS two-component system of Staphylococcus aureus. Molecular Microbiology, 86: 331–348. doi: 10.1111/j.1365-2958.2012.08198.x
- Issue published online: 9 OCT 2012
- Article first published online: 27 AUG 2012
- Accepted manuscript online: 9 AUG 2012 05:42AM EST
- Manuscript Accepted: 1 AUG 2012
- American Heart Association. Grant Number: 0835158N
- National Institute of Allergy and Infectious Diseases. Grant Numbers: AI077564, NIH NIAID AI074658
- Burroughs Wellcome Fund
- National Institute of General Medical Sciences. Grant Number: NIH NIGMS P50GM081892
In bacterial two-component regulatory systems (TCSs), dephosphorylation of phosphorylated response regulators is essential for resetting the activated systems to the pre-activation state. However, in the SaeRS TCS, a major virulence TCS of Staphylococcus aureus, the mechanism for dephosphorylation of the response regulator SaeR has not been identified. Here we report that two auxiliary proteins from the sae operon, SaeP and SaeQ, form a protein complex with the sensor kinase SaeS and activate the sensor kinase's phosphatase activity. Efficient activation of the phosphatase activity required the presence of both SaeP and SaeQ. When SaeP and SaeQ were ectopically expressed, the expression of coagulase, a sae target with low affinity for phosphorylated SaeR, was greatly reduced, while the expression of alpha-haemolysin, a sae target with high affinity for phosphorylated SaeR, was not, demonstrating a differential effect of SaePQ on sae target gene expression. When expression of SaePQ was abolished, most sae target genes were induced at an elevated level. Since the expression of SaeP and SaeQ is induced by the SaeRS TCS, these results suggest that the SaeRS TCS returns to the pre-activation state by a negative feedback mechanism.