Fig. 4.

Structure of MERS-CoV S-2P in complex with G4 Fab. (A) Structure of MERS S-2P ectodomain in complex with G4 Fab as viewed along (Left) and above (Right) the viral membrane. A single protomer of the trimeric S protein is shown in ribbon representation and colored as in the primary structure diagram. The two remaining protomers are shown as molecular surfaces and colored white and gray. CD, connector domain; CH, central helix; Fd, Foldon trimerization domain; SD-1, subdomain 1; SD-2, subdomain 2. (B and C) Magnified view of the S1/S2 (B) and S2′ (C) protease sites. Dashed lines represent disordered residues. Arrows indicate position of protease cleavage.