Journal article
Activation of Bacillus subtilis Ugd by the BY-Kinase PtkA Proceeds via Phosphorylation of Its Residue Tyrosine 70
The phosphorylation-dependent activation of bacterial UDP-glucose dehydrogenases by BY-kinases has been previously described in several bacterial model organisms, but the identity of phosphorylated tyrosine(s) and the exact activation mechanism remained unknown. A recent site-specific phosphoproteomic study indicated that tyrosine 70 is phosphorylated in the Bacillus subtilis UDP-glucose dehydrogenase Ugd.
In this study we confirm that this tyrosine 70 is indeed the main residue phosphorylated by the cognate BY-kinase PtkA. Homology-based modeling of the Ugd structure using structures from UDP-glucose/GDP-mannose dehydrogenases revealed that this residue is in close proximity to the NAD-binding site. We identified lysine 108 as the second important residue involved in Ugd activation.
Enzymatic characterization of the Ugd proteins mutated in residues tyrosine 70 or lysine 108 suggested a phosphorylation-based regulatory mechanism. This study represents the first attempt to understand the activation of a bacterial enzyme by tyrosine phosphorylation at the molecular level.
| Language: | English |
|---|---|
| Publisher: | S. Karger AG |
| Year: | 2009 |
| Pages: | 83-89 |
| ISSN: | 14753774 , 14641801 , 16602412 , 26731673 and 26731665 |
| Types: | Journal article |
| DOI: | 10.1159/000206635 |
| ORCIDs: | Mijakovic, Ivan |
Amino Acid Sequence Amino Acid Substitution Bacillus subtilis Gene Expression Regulation, Bacterial Gene Expression Regulation, Enzymologic Models, Molecular Molecular Sequence Data Mutagenesis, Site-Directed Phosphorylation Protein Kinases Protein Structure, Tertiary Sequence Alignment Tyrosine Uridine Diphosphate Glucose Dehydrogenase
