Undecaprenyl pyrophosphate (C55-PP) (C55-PP)

Undecaprenyl pyrophosphate (C55-PP) is a critical C55-isoprenoid lipid carrier required for the assembly of the bacterial cell wall [PubMed: 16299534]. It serves as the lipid anchor that transports hydrophilic peptidoglycan, teichoic acid, and O-antigen precursors from the cytoplasm across the cell membrane to the periplasmic space [UniProt: P0A6M3]. Once the precursor is transferred to the growing cell wall, C55-PP is released and must be dephosphorylated by specific phosphatases, such as BacA, to regenerate undecaprenyl phosphate (C55-P) for subsequent rounds of transport [PubMed: 22945900]. Because the cellular pool of these lipid carriers is extremely small, the recycling of C55-PP is a vital bottleneck in bacterial metabolism [Nature: 10.1038/ncomms1221]. The antibiotic bacitracin targets this molecule by binding to C55-PP in the presence of divalent metal ions like zinc, forming a stable complex that prevents dephosphorylation [PubMed: 4328831]. This sequestration effectively halts cell wall synthesis, leading to bacterial lysis and death, making it a potent target for antimicrobial therapy [StatPearls: NBK536993].

Other names

Bactoprenol pyrophosphateUndecaprenyl diphosphateC55-isoprenyl pyrophosphateUndecaprenyl-PP

Sequestration of the lipid carrier to prevent dephosphorylation and recycling, thereby inhibiting cell wall biosynthesis.