Escherichia coli outer membrane receptors (E. coli OMRs) (E. coli OMRs)

Escherichia coli outer membrane receptors are specialized proteins, predominantly TonB-dependent receptors (TBDTs), that facilitate the active transport of essential nutrients across the outer membrane (UniProt, 2024). These receptors are vital for the uptake of iron-siderophore complexes, vitamin B12, and other large molecules that cannot pass through standard porin channels (PubMed, PMID: 28257454). Because iron is a limiting factor for bacterial growth during infection, these receptors play a crucial role in the pathogenesis of E. coli-related diseases such as urinary tract infections and sepsis (NCBI, 2022). In pharmacology, these receptors are targeted using the "Trojan horse" approach, where an antibacterial agent is linked to a siderophore to ensure high-efficiency uptake into the bacterium (PubMed, PMID: 31601559). Cefiderocol is a clinically approved siderophore cephalosporin that utilizes these receptors to overcome common resistance mechanisms like porin loss or efflux pump overexpression (DrugBank, 2024). The diversity of these receptors, including FhuA, FepA, and CirA, allows the bacteria to adapt to various host environments, but also provides multiple pathways for drug entry.

Other names

TonB-dependent receptorsTBDTsSiderophore receptorsOuter membrane transport proteinsFhuAFepAFecACirAFiuBtuB

Siderophore-mediated active transport (Trojan horse strategy) where the drug mimics natural ligands to gain entry into the bacterial cell (PubMed, PMID: 31601559).