Fig. 6.

Binding site of GlcNAc on the MAdV-2 fibre head. (a) Omit map (2Fo-Fc) contoured at 1 sigma displayed around the GlcNAc molecule in monomer A. (b) Top or end-of-fibre view of three GlcNAc molecules (yellow) binding between the AB and CD loops of the MAdV-2 fibre head. (c) Close-up of one of the GlcNAc binding sites. Residues with atoms within hydrogen-bonding distance are labelled. Putative hydrogen bonds are marked with black interrupted lines. The sugar ring stacks onto the side-chain of Tyr650 (also labelled). (d) Superposition of the structure of the MAdV-2 fibre head (green) bound to GlcNAc (yellow and red) and the CAdV-2 fibre head bound to sialic acid (PDB 2WBV; slate blue and red).