5UZB

Cryo-EM structure of the MAL TIR domain filament

Summary for 5UZB

• Entry DOI: 10.2210/pdb5uzb/pdb
• EMDB information: 8625
• Descriptor: Toll/interleukin-1 receptor domain-containing adapter protein (1 entity in total)
• Functional Keywords: tir domain, adaptor proteins, tlr signaling, homotypic protein interactions, immune system
• Biological source: Homo sapiens (Human)
• Total number of polymer chains: 14
• Total formula weight: 275648.27

Authors

Ve, T.,Vajjhala, P.R.,Hedger, A.,Croll, T.,DiMaio, F.,Horsefield, S.,Yu, X.,Lavrencic, P.,Hassan, Z.,Morgan, G.P.,Mansell, A.,Mobli, M.,O'Carrol, A.,Chauvin, B.,Gambin, Y.,Sierecki, E.,Landsberg, M.J.,Stacey, K.J.,Egelman, E.H.,Kobe, B. (deposition date: 2017-02-25, release date: 2017-07-26, Last modification date: 2024-11-06)

Primary citation

Ve, T.,Vajjhala, P.R.,Hedger, A.,Croll, T.,DiMaio, F.,Horsefield, S.,Yu, X.,Lavrencic, P.,Hassan, Z.,Morgan, G.P.,Mansell, A.,Mobli, M.,O'Carroll, A.,Chauvin, B.,Gambin, Y.,Sierecki, E.,Landsberg, M.J.,Stacey, K.J.,Egelman, E.H.,Kobe, B.
Structural basis of TIR-domain-assembly formation in MAL- and MyD88-dependent TLR4 signaling.
Nat. Struct. Mol. Biol., 24:743-751, 2017

PubMed Abstract: Toll-like receptor (TLR) signaling is a key innate immunity response to pathogens. Recruitment of signaling adapters such as MAL (TIRAP) and MyD88 to the TLRs requires Toll/interleukin-1 receptor (TIR)-domain interactions, which remain structurally elusive. Here we show that MAL TIR domains spontaneously and reversibly form filaments in vitro. They also form cofilaments with TLR4 TIR domains and induce formation of MyD88 assemblies. A 7-Å-resolution cryo-EM structure reveals a stable MAL protofilament consisting of two parallel strands of TIR-domain subunits in a BB-loop-mediated head-to-tail arrangement. Interface residues that are important for the interaction are conserved among different TIR domains. Although large filaments of TLR4, MAL or MyD88 are unlikely to form during cellular signaling, structure-guided mutagenesis, combined with in vivo interaction assays, demonstrated that the MAL interactions defined within the filament represent a template for a conserved mode of TIR-domain interaction involved in both TLR and interleukin-1 receptor signaling.

PubMed: 28759049
DOI: 10.1038/nsmb.3444

Experimental method

ELECTRON MICROSCOPY (7 Å)