Regulation of glutamine and glutamate metabolism by GlnR and GlnA in Streptococcus pneumoniae
Ontology highlight
ABSTRACT: Several genes involved in nitrogen metabolism are known to contribute to the virulence of pathogenic bacteria. Here, we studied the function of the nitrogen regulatory protein GlnR in the Gram-positive human pathogen Streptococcus pneumoniae. We demonstrate that GlnR mediates transcriptional repression of genes involved in glutamine synthesis and uptake (glnA, glnPQ), glutamate synthesis (gdhA), and the gene encoding the pentose phosphate pathway enzyme Zwf, which forms an operon with glnPQ. Moreover, the expression of gdhA is also repressed by the pleiotropic regulator CodY. The GlnR-dependent regulation occurs through a conserved operator sequence and is responsive to the concentration of glutamate, glutamine and ammonium in the growth medium. By means of in vitro binding studies and transcriptional analyses we show that the regulatory function of GlnR is dependent on GlnA. Mutants of glnA and glnP displayed significantly reduced adhesion to Detroit 562 human pharyngeal epithelial cells, suggesting a role for these genes in the colonization of the host by S. pneumoniae. Thus, our results provide a thorough insight into the regulation of glutamine and glutamate metabolism of S. pneumoniae as mediated by both GlnR and GlnA. Keywords: genetic modification
ORGANISM(S): Streptococcus pneumoniae
PROVIDER: GSE5088 | GEO | 2006/06/23
SECONDARY ACCESSION(S): PRJNA95391
REPOSITORIES: GEO
ACCESS DATA