DBL sequence alignment. The six DBL domains in VAR2CSA are compared to erythrocyte binding proteins. Cysteine residues are highlighted in blue shading and numbered -1 to 12 based on conservation between erythrocyte binding proteins. The end of the sequence homology between PfEMP1 and erythrocyte binding-type DBL domains is indicated with an arrowhead and grey shading of the final F/Y residue. The S1, S2 and S3 subdomains boundaries are indicated by arrows. The start and end residues in the original VAR2CSA DBL constructs are indicated by grey shading. There is a 26 amino acid spacer before the CXC motif in the DBL2 domain. Accession numbers are IT4-VAR2CSA (AAQ73926), EBA-175 (MAL7P1.176), and P. knowlesi α (M90466).