InterPro domain: IPR044704

(S)-ureidoglycine aminohydrolase (UGHY or UGlyAH) is involved in the ureide pathway, a metabolic route of purine catabolism in plants, some bacteria and probably in some fungi where, uric acid is degraded into glyoxylate and ammonia [ 1 ]. This enzyme is involved in the anaerobic nitrogen utilization via the assimilation of allantoin. It catalyses the second step in the allantoin degradation pathway, the deamination of the allantoin producing S-ureidoglycolate and ammonia from S-ureidoglycine [ 2 , 2 ].

The structure of UGlyAH from Arabidopsis thaliana (AtUGlyAH) has been studied. It contains two structurally similar beta-barrel domains, called N and C (cupin) domains. AtUGlyAH binds a Mn ion through its C-terminal domain which acts as a molecular anchor to bind (S)-ureidoglycine. Its structure showed a bi-cupin fold with a conserved jelly roll-like beta-barrel fold and an octameric functional unit. Several structural homologues of UGlyAH, including the Escherichia coli ortholog YlbA (also known as GlxB6), also exhibit similar features [ 3 ].

This entry represents the N-terminal cupin domain found in (S)-ureidoglycine aminohydrolases, including UGlyAH from E.coli and its homologues from plants and fungi [ 4 ].

1. Ureide catabolism in Arabidopsis thaliana and Escherichia coli. Nat. Chem. Biol. 6, 19-21
2. Chemical basis of nitrogen recovery through the ureide pathway: formation and hydrolysis of S-ureidoglycine in plants and bacteria. ACS Chem Biol 5, 203-14
3. Structural and functional insights into (S)-ureidoglycine aminohydrolase, key enzyme of purine catabolism in Arabidopsis thaliana. J Biol Chem 287, 18796-805
4. The ureide-degrading reactions of purine ring catabolism employ three amidohydrolases and one aminohydrolase in Arabidopsis, soybean, and rice. Plant Physiol 163, 672-81