Biosynthesis of the Escherichia coli K1 group 2 polysialic acid capsule occurs within a protected cytoplasmic compartment.

ABSTRACT: Capsular polysaccharides are important virulence determinants in a wide range of invasive infectious diseases. Although capsule synthesis has been extensively investigated, understanding polysaccharide export from the cytoplasm to the external environment has been more difficult. Here we present the results of a novel protection assay indicating that synthesis and export of the Escherichia coli K1 group 2 capsular polysialic acid (K1 antigen) occur within a protected subcellular compartment designated the sialisome. In addition to the polymerase encoded by neuS, localization and complementation analyses indicated that the sialisome includes the accessory membrane protein NeuE. The requirement for NeuE was suppressed by overproducing NeuS, suggesting that NeuE functions by stabilizing the p

SUBMITTER: Steenbergen SM 

PROVIDER: S-EPMC2408645 | biostudies-literature | 2008 Jun

REPOSITORIES: biostudies-literature