Extended Data Fig. 3: Subtomogram averaging of Sed5-bound inner coat.

(A) Surface representation of the 4.1 Å STA map of the inner coat on Sed5-enriched GUV tubules (B) as in (A), with the Sec24-Sec24-Sar1 heterotrimer atomic model fitted. Sec23 in blue, Sec24 in green, Sar1 in yellow. (C) A 20 Å low-pass filtered map of the inner coat mapped back onto a representative section of a tomogram, showing the extensive lattice wrapping around a tubule. (D) and (E), As in Fig. 3E, F, but focussing on the A-site of Sec24, and showing the Sed5 YNNSNPF peptide bound as crystallised (PDB ID: 8PD0, in purple). While extra density in (D) (Sed5-bound) with respect to (E) cannot be excluded, it is difficult to unambiguously detect above the noise.