Members of this protein family are aminohydrolases related to, but distinct from, glutamyl-tRNA(Gln) amidotransferase subunit A. The best characterized member is the biuret hydrolase of Pseudomonas sp. ADP, which hydrolyzes ammonia from the three-nitrogen compound biuret to yield allophanate. Allophanate is also an intermediate in urea degradation by the urea carboxylase/allophanate hydrolase pathway, an alternative to urease. [Unknown function, Enzymes of unknown specificity]