PTS

The PEP:Sugar Phosphotransferase System

The PTS is a sugar transport system that couples the transport of a sugar to its phosphorylation. The phosphate group is derived from phosphoenolpyruvate (PEP) and transferred via the general PTS proteins Enzyme I (EI) and HPr to the substrate-specific Enzymes II (EII) to the incoming sugars.

In addition to its role in sugar transport, the PTS is also involved in the regulation of carbon metabolism.

General PTS proteins

• • Enzyme I
  • HPr

Proteins closely related to the PTS

• • Crh: HPr-like protein with exculsively regulatory functions (His-15 is not conserved)
  • HprK: HPr-kinase, key factor for carbon catabolite repression