Fig. 5: Relative conformations of the apo- and ligand-bound IGF1R ectodomain.
From: Interaction of a viral insulin-like peptide with the IGF-1 receptor produces a natural antagonist
a CryoEM density plus the atomic model of scLCDV-1VILP bound to IGF1R.zip shown in ribbon representation (map contour level 0.149). b CryoEM density associated with scLCDV1-VILP, domain FnIII-1′, αCT´ and domain L1 (map contour level 0.149). c CryoEM structure of IGF1R ectodomain in complex with two copies of scLCDV1-VILP with one receptor monomer in low-resolution surface representation and the other in ribbon representation. Note domains FnIII-3 and FnIII-3´ and upstream regions of the insert domains are positioned based on weak potential density from an initial consensus cryoEM map; these entities are unmodelled in the final deposited structure as they are not discerned in the final potential map. Domains are labeled L1, L2: first and second leucine-rich repeat domains; FnIII-1, -2, -3: first, second and third fibronectin Type III domains; αCT: C-terminal α-helical segment of IGF1R α-chain (prime symbol ´ denotes domains from alternate monomer). d Apo IGF-1R ectodomain crystal structure20 (PDB: 5U8R). Domain representation and nomenclature is as in panel c. e CryoEM structure of a single IGF-1 bound to IGF1R (PDB: 6PYH)37. Domain representation and nomenclature as in c. f, g Relative disposition of scLCDV1-VILPs and (h) IGF-1 upon binding to receptor, illustrating (*) the comparative lack of interaction of the L1´-bound scLCDV1-VILP with domain FnIII-1.
