Fig. 1 |. Structure of the complex of chicken STING and human TBK1.

a, b, Three-dimensional reconstructions of two 3D classes of the complex. The atomic models of dimeric full-length chicken STING bound to cGAMP (from ref.12) and the human TBK1 dimer (RCSB Protein Data Bank (PDB) code 4IM0) were fit into the maps (grey) through rigid-body docking. The extra density that surrounds the transmembrane (TM) domain of STING in a is from the detergent micelle. The protein density in b is stronger and therefore shown at a higher threshold, which led to partial cut-off of the detergent micelle density. LBD, ligand-binding domain. c, High-resolution 3D reconstruction from focused refinement on TBK1 with C2 symmetry. The densities for the two protomers of the TBK1 dimer are coloured either cyan or blue. The densities for the two STING tails are coloured either yellow or green. d, Atomic model of TBK1 bound to the C-terminal tail of STING. The colour scheme is the same as that of the atomic models in a. KD, kinase domain; ULD, ubiquitin-like domain. e, Cartoon model of the STING–TBK1 complex. The double-headed arrow indicates the wobble between TBK1 and STING, owing to flexibility in the STING tail. ER, endoplasmic reticulum.