Figure 1: Substitution of the heparan sulphate-binding region of HVS ORF51 protein. Analysis of the peptide sequence of the 269 amino acid protein indicates that there is an N-terminal signal sequence, 9 N-linked glycosylation sites, a potential heparan sulphate-binding site and a transmembrane domain. In the mutant ORF51 virus the heparan sulphate-binding site, highlighted in red, is replaced with the peptide sequence in blue. This sequence contains the SSTR binding motif.