<p>This family of proteins includes uncharacterised sequences from eukaryotes, cyanobacteria and Leptospira as well as the DREG-2 protein from <taxon tax_id="7227">Drosophila melanogaster</taxon> (Fruit fly) which has been identified as a rhythmically (diurnally) regulated gene [<cite idref="PUB00015520"/>]. This family is a member of the Haloacid Dehalogenase (HAD) superfamily of aspartate-nucleophile hydrolases. The superfamily is defined by the presence of three short catalytic motifs [<cite idref="PUB00003337"/>]. The subfamilies are defined [<cite idref="PUB00009540"/>] based on the location and the observed or predicted fold of a so-called, capping domain, [<cite idref="PUB00009540"/>], or the absence of such a domain. This family is a member of subfamily 1A in which the cap domain consists of a predicted alpha helical bundle found in between the first and second catalytic motifs. A distinctive feature of this family is a conserved tandem pair of tryptophan residues in the cap domain. The most divergent sequences included within the scope of this entry are from plants and have "FW" at this position instead. Most likely, these sequences, like the vast majority of HAD sequences, represent phosphatase enzymes.</p> HAD-superfamily hydrolase, subfamily IA, REG-2-like