Aligned amino acid sequence of 21 anti-Cap specific VHH antibody fragments.
Amino acid sequences were aligned according to the Kabat numbering . The dots denote the same sequences compared with VHH1. Differences in the sequence are shadowed, and the dash shows the missing sequences. The hallmark Cys residues are denoted by the thick-line boxes. The four conservative hallmark residues of VHH in FR2 (Val37Phe, Gly44Glu/Lys, Arg45Leu, and Trp47Gly) are denoted by the dotted line boxes.