Fig. 1. Schematic structure of calpain superfamily members. Names of the gene products are represented by the most familiar one or two names, or, if none exists, by the database accession number. The length of each domain is roughly to scale. Red letters in "Gene Product" indicate that it is a conventional type with a 5EF-hand domain. Dark colors at the active site residues indicate that the corresponding residue is replaced by to another amino acid residue. Abbreviations used are: NS, N-terminal insertion sequence; IS1 and IS2, insertion sequence 1 and 2; AS, alternative splicing products; T, TRA-3-specific domain; N, N-terminal conserved sequence in PalB homologues; PBH, PalB homologous domain; Zn, Zn-finger motif; SOH, SOL homologous domain; DIS, Drosophila insertion sequence; TM, trans-membrane domain; CSTN, calpastatin-like domain.