Peptidoglycan Branched Stem Peptides Contribute to Streptococcus pneumoniae Virulence by Inhibiting Pneumolysin Release.

ABSTRACT: Streptococcus pneumoniae (the pneumococcus) colonizes the human nasopharynx and is a significant pathogen worldwide. Pneumolysin (Ply) is a multi-functional, extracellular virulence factor produced by this organism that is critical for pathogenesis. Despite the absence of any apparent secretion or cell surface attachment motifs, Ply localizes to the cell envelope of actively growing cells. We sought to characterize the consequences of this surface localization. Through functional assays with whole cells and subcellular fractions, we determined that Ply activity and its release into the extracellular environment are inhibited by peptidoglycan (PG) structure. The ability of PG to inhibit Ply release was dependent on the stem peptide composition of this macromolecule, which was manipulated by

SUBMITTER: Greene NG 

PROVIDER: S-EPMC4483231 | biostudies-literature | 2015 Jun

REPOSITORIES: biostudies-literature