Group-3 biosynthesis

Schematic representation of Group-3 capsular polysaccharide biosynthesis and surface assembly

group-3 image

Group-3 Proteins

WbaP : Initial Glycosyl transferase

Wzz : Chain length dictator

WaaL : Polymerization terminator

GTs : Glycosyl transferase

KpsMT : ABC transporters

KpsE :Adaptor protein

KpsD :Outer membrane translocon

  1. The group-3 capsular assembly is similar to group-2 (ABC-transporter pathway)
  2. The genetic loci has undergone recombination leading to different gene positions
  3. The serotype specific domain is centrally located and is flanked by conserved genes on both sides
  4. The structural features and components of the repeat units of group 2 and 3 capsules vary extensively
  5. Group-3 loci lack thermoregulation property and are produced at all temperatures