This family of enzymes are a a large metal dependent hydrolase superfamily [1]. The family includes Adenine deaminase EC:3.5.4.2 that hydrolyses adenine to form hypoxanthine and ammonia. Adenine deaminases reaction is important for adenine utilisation as a purine and also as a nitrogen source [2]. This family also includes dihydroorotase and N-acetylglucosamine-6-phosphate deacetylases, EC:3.5.1.25 These enzymes catalyse the reaction N-acetyl-D-glucosamine 6-phosphate + H2O <=> D-glucosamine 6-phosphate + acetate. This family includes the catalytic domain of urease alpha subunit [3]. Dihydroorotases (EC:3.5.2.3) are also included [4-5].

1: An evolutionary treasure: unification of a broad set of amidohydrolases related to urease. Holm L, Sander C; Proteins 1997;28:72-82. PMID:9144792

2: Role of adenine deaminase in purine salvage and nitrogen metabolism and characterization of the ade gene in Bacillus subtilis. Nygaard P, Duckert P, Saxild HH; J Bacteriol 1996;178:846-853. PMID:8550522

3: The crystal structure of urease from Klebsiella aerogenes. Jabri E, Carr MB, Hausinger RP, Karplus PA; Science 1995;268:998-1004. PMID:7754395

4: Novel organization and sequences of five genes encoding all six enzymes for de novo pyrimidine biosynthesis in Trypanosoma cruzi. Gao G, Nara T, Nakajima-Shimada J, Aoki T; J Mol Biol 1999;285:149-161. PMID:9878395

5: As in Saccharomyces cerevisiae, aspartate transcarbamoylase is assembled on a multifunctional protein including a dihydroorotase-like cryptic domain in Schizosaccharomyces pombe. Lollier M, Jaquet L, Nedeva T, Lacroute F, Potier S, Souciet JL; Curr Genet 1995;28:138-149. PMID:8590465