PslD–PslE Polysaccharide Transport Complex

Continuous Transmembrane Channel

Cryo-EM structures of the PslD–PslE complex reveal a continuous, protected conduit spanning the entire cell envelope, providing a key model for Wzx/Wzy-dependent polysaccharide biosynthesis.

Liu, Jiao · Wang, Lanxin · Ma, Luyan Zulie · Ni, Dongchun · Huang, Yihua

Nature Communications 2026

Advantages

Protected conduit

The PslD-PslE complex forms a continuous channel spanning the entire cell envelope, shielding the polymerizing polysaccharide from periplasmic glycosidases like PslG.

Polymerase positioned

The polymerase PslJ is localized within a membrane lumen formed by the octameric arrangement of PslE's transmembrane helical pairs, coupling polymerization and transport.

Side portal access

Und-PP-linked pentasaccharide units access PslJ through side portals in the PslE octamer, preventing exposure to the periplasm.

Applications

• P. aeruginosa biofilm inhibition：Target the conduit to block polysaccharide export and biofilm formation without killing bacteria.
• Polysaccharide biosynthesis pathway engineering：Use structural insights to engineer the conduit for improved heterologous polysaccharide production.
• Inhibitor design for polysaccharide-processing enzymes：Design inhibitors that bind to the polymerase within its confined chamber to block polymerization.