<p> This group of hydrolase enzymes is structurally different from the alpha/beta hydrolase family (abhydrolase). This group includes L-2-haloacid dehalogenase, epoxide hydrolases and phosphatases. The structure consists of two domains. One is an inserted four helix bundle, which is the least well conserved region of the alignment, between residues 16 and 96 of HAD1_PSESP. The rest of the fold is composed of the core alpha/beta domain.</p>