GONUTS has been updated to MW1.31 Most things seem to be working but be sure to report problems.

Have any questions? Please email us at ecoliwiki@gmail.com


Jump to: navigation, search


You don't have sufficient rights on this wiki to edit tables. Perhaps you need to log in. Changes you make in the Table editor will not be saved back to the wiki

See Help for Help on this wiki. See the documentation for how to use the table editor


Vincent, C, Duclos, B, Grangeasse, C, Vaganay, E, Riberty, M, Cozzone, AJ and Doublet, P (2000) Relationship between exopolysaccharide production and protein-tyrosine phosphorylation in gram-negative bacteria. J. Mol. Biol. 304:311-21


The phosphorylation of proteins at tyrosine residues is known to play a key role in the control of numerous fundamental processes in animal systems. In contrast, the biological significance of protein-tyrosine phosphorylation in bacteria, which has only been recognised recently, is still unclear. Here, we have analysed the role in Escherichia coli cells of an autophosphorylating protein-tyrosine kinase, Wzc, and a phosphotyrosine-protein phosphatase, Wzb, by performing knock-out experiments on the corresponding genes, wzc and wzb, and looking at the metabolic consequences induced. The results demonstrate that the phosphorylation of Wzc, as regulated by Wzb, is directly connected with the production of a particular capsular polysaccharide, colanic acid. Thus, when Wzc is phosphorylated on tyrosine, no colanic acid is synthesised by bacteria, but when dephosphorylated by Wzb, colanic acid is produced. This process is rather specific to the pair of proteins Wzc/Wzb. Indeed, a much lesser effect, if any, on colanic acid synthesis is observed when knock-out experiments are performed on another pair of genes, etk and etp, which also encode respectively a protein-tyrosine kinase, Etk, and a phosphotyrosine-protein phosphatase, Etp, in E. coli. In addition, the analysis of the phosphorylation reaction at the molecular level reveals differences between Gram-negative and Gram-positive bacteria, namely in the number of protein components required for this reaction to occur.


PubMed Online version:10.1006/jmbi.2000.4217


Amino Acid Sequence; Bacterial Proteins; Escherichia coli Proteins; Gene Deletion; Gram-Negative Bacteria/enzymology; Gram-Negative Bacteria/genetics; Gram-Negative Bacteria/growth & development; Gram-Negative Bacteria/metabolism; Gram-Positive Bacteria/enzymology; Gram-Positive Bacteria/genetics; Gram-Positive Bacteria/metabolism; Membrane Proteins; Molecular Sequence Data; Phosphorylation; Phosphotyrosine/metabolism; Polysaccharides/biosynthesis; Protein Tyrosine Phosphatases/genetics; Protein Tyrosine Phosphatases/metabolism; Protein-Tyrosine Kinases/chemistry; Protein-Tyrosine Kinases/genetics; Protein-Tyrosine Kinases/metabolism; Sequence Alignment; Substrate Specificity