<p>The composite domain of metal-dependent hydrolases has a pseudo-barrel fold that is interrupted by the catalytic beta/alpha barrel domain. This domain is found in a variety of bacterial and fungal enzymes, including: cytosine deaminase, an enzyme that is important in the pyrimidine salvage pathway [<cite idref="PUB00014255"/>]; the alpha-subunit of urease, a virulence factor of gastric pathogens such as <taxon tax_id="210">Helicobacter pylori</taxon> (Campylobacter pylori) [<cite idref="PUB00014256"/>]; D- and L-hydantoinases (dihydropyrimidinase), which catalyse the production of D- and L-amino acids, respectively [<cite idref="PUB00014257"/>]; isoaspartyl dipeptidase from <taxon tax_id="562">Escherichia coli</taxon>, which functions in protein degradation [<cite idref="PUB00014258"/>]; N-acetylglucosamine-6-phosphate deacetylase, which is an enzyme from the biosynthetic pathway to amino-sugar-nucleotides [<cite idref="PUB00014260"/>]; and N-acyl-D-amino acid amidohydrolase (D-aminoacylase), involved in the synthesis of D-amino acids [<cite idref="PUB00014261"/>].</p>