Structural basis of TLR5-flagellin recognition and signaling.
Yoon, S.I., Kurnasov, O., Natarajan, V., Hong, M., Gudkov, A.V., Osterman, A.L., Wilson, I.A.(2012) Science 335: 859-864
- PubMed: 22344444
- DOI: https://doi.org/10.1126/science.1215584
- Primary Citation of Related Structures:
3V44, 3V47 - PubMed Abstract:
Toll-like receptor 5 (TLR5) binding to bacterial flagellin activates signaling through the transcription factor NF-κB and triggers an innate immune response to the invading pathogen. To elucidate the structural basis and mechanistic implications of TLR5-flagellin recognition, we determined the crystal structure of zebrafish TLR5 (as a variable lymphocyte receptor hybrid protein) in complex with the D1/D2/D3 fragment of Salmonella flagellin, FliC, at 2.47 angstrom resolution. TLR5 interacts primarily with the three helices of the FliC D1 domain using its lateral side. Two TLR5-FliC 1:1 heterodimers assemble into a 2:2 tail-to-tail signaling complex that is stabilized by quaternary contacts of the FliC D1 domain with the convex surface of the opposing TLR5. The proposed signaling mechanism is supported by structure-guided mutagenesis and deletion analyses on CBLB502, a therapeutic protein derived from FliC.
Organizational Affiliation:
Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.