FimH adhesin of uropathogenic Escherichia coli (FimH)

FimH is a mannose-specific adhesin located at the tip of type 1 fimbriae on uropathogenic Escherichia coli. It mediates the initial attachment of bacteria to host tissues by binding specifically to D-mannose residues present on glycoproteins such as uroplakin Ia in the bladder epithelium. This interaction is critical for colonization and pathogenesis in urinary tract infections. The protein consists of two domains—a lectin domain responsible for mannose recognition and a pilin domain anchoring it to the fimbria—and exhibits conformational changes that regulate its affinity for ligands, including a unique "catch bond" mechanism where binding strength increases under shear stress conditions typical of urine flow. Structural studies have revealed that FimH can bind various mannoside ligands with high specificity, making it an attractive target for antiadhesive therapies aimed at preventing or treating UTIs by blocking bacterial adherence rather than killing bacteria directly. Variations and mutations within FimH influence its receptor-binding properties and contribute to adaptation across different ecological niches within hosts.

Other names

Type 1 fimbrial adhesinMannose-specific adhesinAdhesin protein fimH

Competitive inhibition of FimH-mannose binding, preventing bacterial attachment to host urothelial cells