Bacteria like sharing their sweets.

Protein glycosylation and capsular polysaccharide formation are increasingly recognized as playing central roles in the survival and virulence of bacterial pathogens. In this issue of Molecular Microbiology, structural analysis in Acinetobacter baumannii 17978 revealed that a pentasaccharide that decorates glycoproteins is formed of the same building blocks used for capsule biosynthesis demonstrating split roles for this glycan. Disruption of PglC, the initiating glycosyltransferase responsible for attachment of the first sugar to undecaprenylphosphate abolished glycoprotein production and capsule biosynthesis. Both pathways are demonstrated to be important in biofilm formation and pathogenesis, and disabling their synthesis should provide a useful route for antimicrobial design. Shared polysaccharide usage reduces the genetic and metabolic burden in a bacterial cell and is an emerging theme among bacterial pathogens that need to be energy efficient for their streamlined lifestyle.