title: Structural basis for specific recognition of single-stranded RNA by Toll-like receptor 13.
abstract: Toll-like receptors (TLRs) have crucial roles in innate immunity, functioning as pattern-recognition receptors. TLR13 recognizes a conserved sequence from bacterial 23S rRNA and then triggers an immune response. Here we report the crystal structure of the mouse TLR13 ectodomain bound by a 13-nt single-stranded (ss) RNA derived from 23S rRNA. The ssRNA induces TLR13 dimerization but assumes a stem-loop-like structure that is completely different from that in the bacterial ribosome but nevertheless is crucial for TLR13 recognition. Most of the RNA nucleotides are splayed out to make base-specific contacts with the concave surface of TLR13, and RNA-specific interactions are important to allow TLR13 to distinguish RNA from DNA. Interestingly, a viral-derived 16-nt ssRNA predicted to form a similar stem-loop-like structure also induces TLR13 activation. Together, our results reveal the structural mechanism of TLR13's sequence- and conformation-specific recognition of ssRNA.
authors: Ministry of Education Key Laboratory of Protein Science, Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China.|Tsinghua-Peking Center for Life Sciences, Beijing, China.
authors: Wen
authors: W
authors: Song
authors: Ministry of Education Key Laboratory of Protein Science, Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China.|Tsinghua-Peking Center for Life Sciences, Beijing, China.
authors: Jia
authors: J
authors: Wang
authors: Ministry of Education Key Laboratory of Protein Science, Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China.|Tsinghua-Peking Center for Life Sciences, Beijing, China.
authors: Zhifu
authors: Z
authors: Han
authors: Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M University Health Science Center, Houston, Texas, USA.
authors: Yifan
authors: Y
authors: Zhang
authors: Ministry of Education Key Laboratory of Protein Science, Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China.
authors: Heqiao
authors: H
authors: Zhang
authors: Ministry of Education Key Laboratory of Protein Science, Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China.
authors: Weiguang
authors: W
authors: Wang
authors: Collaborative Innovation Center of New Drug Research and Safety Evaluation, Zhengzhou University, Zhengzhou, China.
authors: Junbiao
authors: J
authors: Chang
authors: Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M University Health Science Center, Houston, Texas, USA.
authors: Bingshu
authors: B
authors: Xia
authors: Ministry of Education Key Laboratory of Protein Science, Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China.|Tsinghua-Peking Center for Life Sciences, Beijing, China.
authors: Shilong
authors: S
authors: Fan
authors: Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M University Health Science Center, Houston, Texas, USA.
authors: Dekai
authors: D
authors: Zhang
authors: Ministry of Education Key Laboratory of Protein Science, Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China.
authors: Jiawei
authors: J
authors: Wang
authors: Ministry of Education Key Laboratory of Protein Science, Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China.|Tsinghua-Peking Center for Life Sciences, Beijing, China.
authors: Hong-Wei
authors: HW
authors: Wang
authors: Ministry of Education Key Laboratory of Protein Science, Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China.|Tsinghua-Peking Center for Life Sciences, Beijing, China.
authors: Jijie
authors: J
authors: Chai
mesh_terms: D000818:Animals; D002850:Chromatography, Gel; D020285:Cryoelectron Microscopy; D003460:Crystallization; D019281:Dimerization; D007091:Image Processing, Computer-Assisted; D008156:Luciferases; D051379:Mice; D046529:Microscopy, Electron, Transmission; D008958:Models, Molecular; D009841:Oligonucleotides / Q000235:genetics; D011485:Protein Binding; D011487:Protein Conformation; D012338:RNA, Ribosomal, 23S / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D051193:Toll-Like Receptors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
chemical_list: D009841:Oligonucleotides; D012338:RNA, Ribosomal, 23S; C539093:Tlr13 protein, mouse; D051193:Toll-Like Receptors; D008156:Luciferases