Download MendeleyA conserved TLR5 binding and activation hot spot on flagellin
Song, W.S., Jeon, Y.J., Namgung, B., Hong, M., Yoon, S.I.(2017) Sci Rep 7: 40878-40878
- PubMed: 28106112
- DOI: https://doi.org/10.1038/srep40878
- Primary Citation of Related Structures:
5GY2 - PubMed Abstract:
Flagellin is a bacterial protein that polymerizes into the flagellar filament and is essential for bacterial motility. When flagellated bacteria invade the host, flagellin is recognized by Toll-like receptor 5 (TLR5) as a pathogen invasion signal and eventually evokes the innate immune response. Here, we provide a conserved structural mechanism by which flagellins from Gram-negative γ-proteobacteria and Gram-positive Firmicutes bacteria bind and activate TLR5. The comparative structural analysis using our crystal structure of a complex between Bacillus subtilis flagellin (bsflagellin) and TLR5 at 2.1 Å resolution, combined with the alanine scanning analysis of the binding interface, reveals a common hot spot in flagellin for TLR5 activation. An arginine residue (bsflagellin R89) of the flagellin D1 domain and its adjacent residues (bsflagellin E114 and L93) constitute a hot spot that provides shape and chemical complementarity to a cavity generated by the loop of leucine-rich repeat 9 in TLR5. In addition to the flagellin D1 domain, the D0 domain also contributes to TLR5 activity through structurally dispersed regions, but not a single focal area. These results establish the groundwork for the future design of flagellin-based therapeutics.
Organizational Affiliation:
Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon 24341, Republic of Korea.
