Editor: Marco Soria
Requirements for the phosphorylation of the Escherichia coli EIIANtr protein in vivo
Article first published online: 8 JUL 2008
© 2008 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved
FEMS Microbiology Letters
Volume 286, Issue 1, pages 96–102, September 2008
How to Cite
Zimmer, B., Hillmann, A. and Görke, B. (2008), Requirements for the phosphorylation of the Escherichia coli EIIANtr protein in vivo. FEMS Microbiology Letters, 286: 96–102. doi: 10.1111/j.1574-6968.2008.01262.x
- Issue published online: 23 JUL 2008
- Article first published online: 8 JUL 2008
- Received 23 April 2008; accepted 4 June 2008.First published online 8 July 2008.
- protein phosphorylation;
- phosphoenolpyruvate-dependent phosphotransferase system (PTS);
The nitrogen-related phosphotransferase system (Ntr-PTS) is a paralogous system working in parallel to the well-known carbohydrate:PTS. In a chain of phosphotransfer reactions, EINtr and NPr (PtsO) deliver phosphoryl groups to the EIIANtr (PtsN) protein. EIIANtr is implicated in important regulatory processes such as the σE-dependent cell envelope stress response and regulation of K+ uptake. Phosphorylation is believed to trigger the output of EIIANtr in these regulations. EIIANtr is encoded within the gene cluster ptsN–yhbJ–ptsO, which is highly conserved in Proteobacteria. In this study, we investigated the phosphorylation of the Escherichia coli EIIANtr protein in vivo by 32P-labeling. We show that EIIANtr is readily phosphorylated in wild-type cells. This phosphorylation occurs at a single site, the histidine 73 in EIIANtr. YhbJ and NPr are dispensable for this phosphorylation. A detailed analysis revealed that both the energy coupling phosphotransferases of the Ntr-PTS as well as the ‘sugar’-PTS contribute to the phosphorylation of EIIANtr, suggesting cross talk between both systems.