Dihydropyrimidinase (IPR030633)

Short name: Dihydropyrimidinase

Overlapping homologous superfamilies

Family relationships


5,6-Dihydropyrimidine amidohydrolase or dihydropyrimidinase (DHPase) catalyses the second step of the reductive pyrimidine degradation, the reversible hydrolytic ring opening of dihydropyrimidines [PMID: 12626710]. Primarily converts 5,6-dihydrouracil to N-carbamyl-beta-alanine (also called 3-ureidopropanoate) and of 5,6-dihydrothymine to N-carbamyl-beta-amino isobutyrate, but also acts on hydantoin and succinimides [PMID: 10656811], which led to the hypothesis that DHPase is identical to the enzyme hydantoinase (HYD), the bacterial counterpart. However, the DHPases from Saccharomyces kluyveri and Dictyostelium discoideum do not hydrolyse hydantoins [PMID: 12626710], and not all HYD hydrolyse dihydropyrimidines, and are therefore not likely to be involved in the reductive pyrimidine catabolism [PMID: 9537960, PMID: 10222578]. As an integral part of the pyrimidine catabolic pathway in eukaryotes, DHPase activity is required for the regulation of the pyrimidine pool size available for nucleic acid synthesis and for supplying the cell with beta-alanine.

The bacterial counterparts of dihydrothymine (DHP), also called hydantoinases (HYD), are used in industry for the synthesis of antibiotics, peptide hormones, and pesticides [PMID: 10098273, PMID: 10222578, PMID: 11849938]. Their natural substrates are often unknown.

The crystal structures of dihydropyrimidinases from yeast and slime mold revealed that yeast dihydropyrimidinase is closer to hydantoinases, whereas the slime mold enzyme shows higher similarity to collapsin-response mediator proteins involved in neuron development [PMID: 16517602]. These enzymes are metalloenzymes [PMID: 7765480, PMID: 6639068].

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.