Multiple sequence alignments and consensus sequences for 11-1F4-binding phage peptides. Phage peptides were aligned (28) and divided into Groups I and II, based on the presence of one of the two proline (-X-Pro-X- and Pro-X-Pro) or cysteine (-le/Leu-Cys and Ile/Leu-X-Cys-) motifs, and each group adjusted to give the best alignment with the N-terminal sequence of VL Len. The hydrophobic and/or aromatic residues are bolded and prolines underlined. Phage peptide consensus sequences were determined using the program CONSENSUS (http://www.bork.embl-heidelberg.de/Alignment/). Abbreviations include: a, aromatic (F, H, Y, W); h, hydrophobic, (A, C, F, I, L, M, V); l, aliphatic (I, L, V); o, S or T; p, polar (D, E, G, H, K, N, P, Q, R, S, T, W, Y); s, small side chain (A, C, D, G, N, P, S, T, V) (31), and each uppercase letter represents the particular amino acid.