Early molecular-recognition events in the synthesis and export of group 2 capsular polysaccharides.
The outer membrane (OM) of almost all Gram-negative bacteria is composed of phospholipids, lipopolysaccharide, proteins and capsular or loosely adherent polysaccharides that together mediate cellular interactions with diverse environments. Most OM components are synthesized intracellularly or at the inner membrane (IM) and thus require an export mechanism. This mini-review focuses on recent progress in understanding how synthesis of one kind of capsular polysaccharide (group 2) is coupled to the export apparatus located in the IM and spanning the periplasmic space, thus providing a transport channel to the cell surface. Although the model system for these investigations is the medically important extraintestinal pathogen Escherichia coli K1 and its polysialic acid capsule, the conclusions are general for other group 2 and group 2-like polysaccharides synthesized by many different bacterial species.
Vimr
Eric R
ER
Laboratory of Sialobiology, Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
Steenbergen
Susan M
SM
Laboratory of Sialobiology, Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
D016667:Bacterial Capsules / Q000096:biosynthesis* / Q000378:metabolism*; D001692:Biological Transport; D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial
D029968:Escherichia coli Proteins