How Tyrosine Phosphorylation Affects the UDP-Glucose Dehydrogenase Activity of <i>Bacillus subtilis </i>YwqF

Vol. 8, No. 1, 2004

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Research Article

How Tyrosine Phosphorylation Affects the UDP-Glucose Dehydrogenase Activity of Bacillus subtilis YwqF
Ivan Mijakovic^a, Dina Petranovic^b, Josef Deutscher^a

^aMicrobiologie et Génétique Moléculaire, CNRS/INRA/INA-PG UMR 2585, Thiverval-Grignon, and
^bLaboratoire de Génétique Microbienne, CRJ-INRA, Jouy en Josas, France

Address of Corresponding Author

J Mol Microbiol Biotechnol 2004;8:19-25 (DOI: 10.1159/000082077)

Key Words

UDP-glucose dehydrogenase
Exopolysaccharide
Substrate inhibition
Tyrosine kinase
Tyrosine phosphatase

Abstract

The UDP-glucose dehydrogenase activity of Bacillus subtilis YwqF is regulated by reversible phosphorylation on a tyrosine residue. This reaction, which is catalyzed by the protein-tyrosine kinase YwqD, activates the enzyme, while dephosphorylation of phosphotyrosine-YwqF by the phosphotyrosine-protein phosphatase YwqE reduces its enzyme activity. Our kinetic data indicate that the phosphorylated and unphosphorylated forms of YwqF differ in binding the substrates. The UDP-glucose dehydrogenase reaction catalyzed by YwqF is inhibited by one of its substrates, UDP-glucose, and the extent of this inhibition seems to be reduced upon YwqF phosphorylation. We propose that this effect could at least partly account for the observed activation of YwqF induced by tyrosine phosphorylation. Potential physiological implications of this finding are discussed.

Author Contacts

Ivan Mijakovic, PhD
Microbial Physiology and Genetics Group, BioCentrum
Technical University of Denmark
DK-2800 Lyngby (Denmark)
Tel. +45 45252508, Fax +45 45932809, E-Mail im@biocentrum.dtu.dk

Article Information

Number of Print Pages : 7
Number of Figures : 4, Number of Tables : 0, Number of References : 22

Medline Abstract (ID 15741737)

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