Molecular insights into capsular polysaccharide secretion.

ABSTRACT: Capsular polysaccharides (CPSs) fortify the cell boundaries of many commensal and pathogenic bacteria¹. Through the ABC-transporter-dependent biosynthesis pathway, CPSs are synthesized intracellularly on a lipid anchor and secreted across the cell envelope by the KpsMT ABC transporter associated with the KpsE and KpsD subunits^1,2. Here we use structural and functional studies to uncover crucial steps of CPS secretion in Gram-negative bacteria. We show that KpsMT has broad substrate specificity and is sufficient for the translocation of CPSs across the inner bacterial membrane, and we determine the cell surface organization and localization of CPSs using super-resolution fluorescence microscopy. Cryo-electron microscopy analyses of the KpsMT-KpsE complex in six differe

SUBMITTER: Kuklewicz J 

PROVIDER: S-EPMC11041684 | biostudies-literature | 2024 Apr

REPOSITORIES: biostudies-literature