Browse by author
Lookup NU author(s): Dr Sven Halbedel
Full text for this publication is not currently held within this repository. Alternative links are provided below where available.
Glycerol is one of the few carbon sources that can be utilized by Mycoplasma pneumoniae. Glycerol metabolism involves uptake by facilitated diffusion, phosphorylation, and the oxidation of glycerol 3-phosphate to dihydroxyacetone phosphate, a glycolytic intermediate. We have analyzed the expression of the genes involved in glycerol metabolism and observed constitutive expression irrespective of the presence of glycerol or preferred carbon sources. Similarly, the enzymatic activity of glycerol kinase is not modulated by HPr-dependent phosphorylation. This lack of regulation is unique among the bacteria for which glycerol metabolism has been studied so far. Two types of enzymes catalyze the oxidation of glycerol 3-phosphate: oxidases and dehydrogenases. Here, we demonstrate that the enzyme encoded by the M. pneumoniae glpD gene is a glycerol 3-phosphate oxidase that forms hydrogen peroxide rather than NADH2. The formation of hydrogen peroxide by GlpD is crucial for cytotoxic effects of M. pneumoniae. A glpD mutant exhibited a significantly reduced formation of hydrogen peroxide and a severely reduced cytotoxicity. Attempts to isolate mutants affected in the genes of glycerol metabolism revealed that only the glpD gene, encoding the glycerol 3-phosphate oxidase, is dispensable. In contrast, the glpF and glpK genes, encoding the glycerol facilitator and the glycerol kinase, respectively, are essential in M. pneumoniae. Thus, the enzymes of glycerol metabolism are crucial for the pathogenicity of M. pneumoniae but also for other essential, yet-to-be-identified functions in the M. pneumoniae cell. Copyright © 2009, American Society for Microbiology. All Right Reserved.
Author(s): Hames C, Halbedel S, Hoppert M, Frey J, Stulke J
Publication type: Article
Publication status: Published
Journal: Journal of Bacteriology
Year: 2009
Volume: 191
Issue: 3
Pages: 747-753
ISSN (print): 0021-9193
ISSN (electronic): 1067-8832
Publisher: American Society for Microbiology
URL: http://dx.doi.org/10.1128/JB.01103-08
DOI: 10.1128/JB.01103-08
PubMed id: 19028882
Altmetrics provided by Altmetric
