Fig. 1: The deAMPylation complex crystal structure.
a The deAMPylation complex crystal structure is colour-coded to illustrate its (sub)domain organisation. The ATP-state structure of isolated BiP-AMP (PDB 5O4P, light grey)4 is superimposed via alignment of its NBD. See Supplementary Fig. 1b–d. b A focus on the two intermolecular interaction surfaces. Selected interdomain contacting residues are shown. Polar interactions are depicted by pink dashed lines. Residues mutated in this study are shown in green. i The interaction of FICD(TPR1) with the tripartite BiP surface (NBD-linker-SBDβ) is highlighted alongside the intramolecular contacts between the FICD’s TPR and Fic domain. ii The intermolecular β-sheet formed between the Fic domain flap (brown) and the Thr518 bearing BiP(SBDβ) loop (ℓ7,8) are highlighted. Note, this sequence-independent mode of substrate engagement is characteristic of Fic proteins15,18 (see Supplementary Fig 2). c Superposition of two heterodimeric crystal structures (purple BiPs and yellow FICDs) with an FICD dimer structure (PDB 4U0U, grey)24. The α-helical BiP lid (SBDα, green, missing from the heterodimeric crystal structure) is modelled by alignment with the full-length BiP:ATP structure (PDB 5E84)71. The N-terminal unstructured region of FICD is shown in the context of an ER membrane24 (see Supplementary Movie 1).
