Fig. 3. Cryo-EM structure of BF-37°C-2D22-NGC (Class II).
(A) Cryo-EM map of BF-37°C-2D22-NGC (Class II) (left) and the fitted structure of the variable region of the Fab complexed with E dimers on a raft (right). The Fab 2D22 heavy and light chains are colored in violet and cyan, respectively. (B) (i) The E proteins of BF-37°C-2D22-NGC are on a higher radius than those of 4°C-2D22-NGC or DENV2(NGC) stage 1. (ii) The E protein arrangement of BF-37°C-2D22-NGC is more similar to that of the 37°CDENV2(NGC) (stage 3) structure (top). The A-C′ dimer of BF-37°C-2D22-NGC is on a slightly higher radius, whereas the B-B′ are located lower when compared to the stage 3 NGC structure. (C) Postulated movement of the Fab-E protein complex from the 4°C-2D22-NGC to the BF-37°C-2D22-NGC structures. The partial lifting and rotation of the A-C dimers would knock off the bound Fab on the B-B′ dimer (zoomed-in panel). This may then be followed by the rotation of the B-B′ dimer.