Exploiting near-atomic resolution single particle reconstruction of macromolecules with small size

1) Replication and transcription of influenza virus genome mainly depend on its RNA-dependent RNA polymerase (RdRP), composed of the PA, PB1, and PB2 subunits. Although extensively studied, the underlying mechanism of the RdRP complex is still unclear. Using single-particle cryo-electron microscopy, we have reconstructed the RdRP tetramer complex at 4.3 Å, highlighting the assembly and interfaces between monomers within the tetrameric structure.

Chang S, Sun D, Liang H, Wang J, Li J, Guo L, Wang X, Guan C, Boruah BM, Yuan L, Feng F, Yang M, Wang L, Wang Y, Wojdyla J, Li L, Wang J, Wang M, Cheng G, Wang HW*, Liu Y*. (2015) Cryo-EM Structure of Influenza Virus RNA Polymerase Complex at 4.3 Å Resolution. Mol. Cell, 57:925-935 (*co-corresponding authors)

2) 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. In a collaboration work with Prof. Jiawei Wang and Jijie Chai at Tsinghua University, we developed a new set of approaches to solve the phasing problem of X-ray crystallography structural determination of the TLR13-RNA complex (300kDa as a dimer) using single particle cryo-EM reconstruction. My lab obtained the complex’s cryo-EM structure at 5 Å resolution and Prof. Jiawei Wang solved the crystal structure at 2.5 Å resolution using the EM map as initial phase information. This work was a very nice synergetic combination of X-ray crystallography with cryo-EM in structural biology and evealed important insights into innate immunity.

Song W, Wang J, Han Z, Zhang Y, Zhang H, Wang W, Chang J, Xia B, Fan S, Zhang D, Wang J*, Wang HW*, Chai J*. (2015) Structural basis for specific recognition of single-stranded RNA by Toll-like receptor 13. Nat. Struct. Mol. Biol., 22:782-787 (*co-corresponding authors)