FIG 4.

A visual representation of how the shift of a glycan from N448 to N446 in the absence of a glycan at N295 may lead to a higher glycan density and, therefore, a better binding environment for Grft. (Left) gp120 monomer, with the relevant glycan sites in cluster 3 (N295, N332, N448) being indicated. (Right) gp120 with the amino acid at position 446 (red) to show its proximity to cluster 3 (circled in red) if it is mutated to Asn to become a glycosite. The structure has PDB accession number 5FYK (118) and was modeled using the UCSF Chimera program (119, 120).