Disease relevance of C00499

• Allantoinase (allantoin amidohydrolase, EC 3.5.2.5.) and allanoicase (allantoate amidinohydrolase, EC 3.5.3.4) of Pseudomonas aeruginosa are inducible enzymes, whose syntheses are enhanced by the presence of allantoin, allantoate, ureidoglycolate, N-carbamoyl-L-asparagine, N-carbamoyl-L-aspartate, hydantoate, and diureidomethane [1].

High impact information on C00499

• DAL5 is a constitutively expressed allantoin system gene whose product is required for allantoate transport [2].
• This study reports the cloning of a cDNA encoding bullfrog (Rana catesbeiana) allantoinase, an enzyme that converts allantoin to allantoic acid [3].
• Allantoinase (allantoin amidohydrolase, EC 3.5.2.5) catalyzes the conversion of allantoin to allantoic acid in the final step of ureide biogenesis [4].
• In leaves of nitrogen-fixing legumes, this reductase may also be involved in ureide breakdown, utilizing the glyoxylate produced during allantoate metabolism [5].
• This sequence, which we term Arabidopsis thaliana Allantoate Amidohydrolase (AtAAH), was shown to be functional by complementation of Saccharomyces cerevisiae dal2 mutants, blocked in allantoate degradation [6].

Biological context of C00499

• Allantoate uptake appears to be mediated by an energy-dependent active transport system with an apparent Michaelis constant of about 50 microM [7].
• We determined the nucleotide sequence of the DAL5 gene, which encodes a component of the allantoate transport system [8].
• We expressed HyuA as a maltose binding protein fusion protein and AllB in its native form and then purified each of them by conventional procedures. allB was found to encode a tetrameric allantoinase (453 amino acids) which specifically hydrolyzes the purine metabolite allantoin to allantoic acid [9].
• SpVht1p belongs to the family of allantoate transporters and has only little sequence homology to the S. cerevisiae biotin transporter [10].

Anatomical context of C00499

• The latter two characteristics are shared with the allantoin uptake system and may result from the sequestering of intracellular allantoate within the cell vacuole [7].
• Allantoin and allantoic acid are also present in the haemolymph and fat body of the larva in varying concentrations [11].

Associations of C00499 with other chemical compounds

• Ureidosuccinate is transported by the allantoate transport system in Saccharomyces cerevisiae [12].
• Mixtures of purine nucleotides, nucleosides, nucleobases, uric acid, allantoin and allantoic acid were fractionated by high-performance liquid chromatography on a polyvinyl alcohol gel column, Asahipak GS-320H, with isocratic elution by sodium phosphate [13].
• The allantoate-degrading enzyme with small molecular weight contained no activity of either ureidoglycolate-degrading enzyme or urease [14].
• Allantoate degradation was demonstrated in the extracts of ungerminated seeds and roots, stems and leaves in germinated seedlings of French bean (Phaseolus vulgaris L.). Activity of allantoate-degrading enzyme could only be measured when phenylhydrazine was included in the assay mixture [14].

Gene context of C00499

• Mutants (dal5) that lack allantoate transport have been isolated [15].
• Allantoin transport (DAL4 gene) is inducible, while allantoate uptake is constitutive (it occurs at full levels in the absence of any allantoate-related compounds from the culture medium) [15].
• Allantoate amidinohydrolase was reported to be the pathway of degradation in studies using the cultivar Maple Arrow and allantoate amidohydrolase was the pathway that existed in the cultivar Williams [16].

References