Structural basis for recognition of N-formyl peptides as pathogen-associated molecular patterns

Nat Commun. 2022 Sep 5;13(1):5232. doi: 10.1038/s41467-022-32822-y.

Abstract

The formyl peptide receptor 1 (FPR1) is primarily responsible for detection of short peptides bearing N-formylated methionine (fMet) that are characteristic of protein synthesis in bacteria and mitochondria. As a result, FPR1 is critical to phagocyte migration and activation in bacterial infection, tissue injury and inflammation. How FPR1 distinguishes between formyl peptides and non-formyl peptides remains elusive. Here we report cryo-EM structures of human FPR1-Gi protein complex bound to S. aureus-derived peptide fMet-Ile-Phe-Leu (fMIFL) and E. coli-derived peptide fMet-Leu-Phe (fMLF). Both structures of FPR1 adopt an active conformation and exhibit a binding pocket containing the R2015.38XXXR2055.42 (RGIIR) motif for formyl group interaction and receptor activation. This motif works together with D1063.33 for hydrogen bond formation with the N-formyl group and with fMet, a model supported by MD simulation and functional assays of mutant receptors with key residues for recognition substituted by alanine. The cryo-EM model of agonist-bound FPR1 provides a structural basis for recognition of bacteria-derived chemotactic peptides with potential applications in developing FPR1-targeting agents.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chemotactic Factors / metabolism
  • Escherichia coli / genetics
  • Escherichia coli / metabolism
  • Humans
  • N-Formylmethionine Leucyl-Phenylalanine / chemistry
  • Neutrophils / metabolism
  • Pathogen-Associated Molecular Pattern Molecules* / metabolism
  • Peptides / metabolism
  • Staphylococcus aureus* / metabolism

Substances

  • Chemotactic Factors
  • Pathogen-Associated Molecular Pattern Molecules
  • Peptides
  • N-Formylmethionine Leucyl-Phenylalanine