Crystal structure of HSV-2 gD–E317-Fab. (a) Ribbon diagram of the HSV-2 gD–E317-Fab complex. gD is coloured blue and magenta and the N-linked oligosaccharides are shown as sticks. The heavy and light chains of E317-Fab are shown in green and orange, respectively. (b) Ribbon representation of HSV-2 gD (residues 25–254). Disulfide bonds, two glycosylation sites (Asn94 and Asn121) and the secondary-structure elements are labelled (Carfí et al., 2001). The inset shows the Asn94-linked N-acetylglucosamine (GlcNAc) bound to Gln41. (c) OMIT maps of glycans. Fo − Fc OMIT maps (orange) were calculated for the two N-linked oligosaccharides and contoured at the 2.0σ level. The glycans and glycan-binding residues are shown as stick models. (d) Comparison of E317-Fab. E317-Fab bound to HSV-2 gD (shown in green) and E317-Fab in its unbound form (pink and magenta) are superimposed in the top view. The N-termini and CDRs are indicated.