Fig 2.

Structural overview of MERS-CoV spike (S) protein. (A) Cryo-EM structure of MERS-CoV S protein trimer (PDB 5X5F). The 3 S monomers are colored in yellow, blue and light coral, respectively. (B) Close-up views of MERS-CoV receptor-binding domain (RBD) and N-terminal domain (NTD) in the S1 subunit of S protein. (C) Crystal structure of MERS-CoV RBD in complex with the receptor human dipeptidyl peptidase 4 (DPP4) (PDB 4KR0). The human DPP4 is colored in orchid. (D) Crystal structure of MERS-CoV RBD in complex with neutralizing monoclonal antibody (mAb) m336 Fab (PDB 4XAK). The m336 Fab is colored in dark green and blue. (E) Crystal structure of MERS-CoV S1-NTD in complex with neutralizing mAb G2 Fab (PDB 6PXH). The G2 Fab is colored in light green and tan. (For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.)