Figure 1. Protein sequence alignment of select cystatins. The aligned sequences extend from 2-3 residues N-terminal to the conserved glycine to the known C-terminal. The alignment was generated and formated essentially as described (Dickinson, 2002). The gaps around the N39 residue involved in legumain inhibition were adjusted manually. Abbreviations used: SA S, SN, D, C, E/M, and F: the corresponding human type 2 cystatins (GenBank accession numbers NP_001313, NP_001890, NP_001889, NP_001891, NP_000090, NP_001314, and NP_003641, respectively); Rat S, rat salivary cystatin S (P19313); chicken, chicken egg white cystatin (P01038); adder, puff adder (Bitis arietans) venom cystatin (P08935); crab, horseshoe crab Tachypleus tridentatus hemocyte cystatin (JC4536); C. elegans, Caenorhabditis elegans cystatin R01B10.1 (NP_504565); and rice, oryzacystatin I (P09229). A majority consensus sequence and the conserved disulfide bonds are shown below the alignment. The positions of conserved domains are indicated above the alignment (see text). Numbers above the alignment indicate residue number (with the conserved glycine numbered position 11 [cystatin C numbering]). Secondary structure regions (based on chicken cystatin, see text) are indicated above. ß-A to ß-E denote the five ß-strands. -1 denotes -helix 1; -2/loop denotes the region that forms an -helix in the crystal, but a loop in solution (see text).