Misplaced Pages

In enzymology, a diaminohydroxyphosphoribosylaminopyrimidine deaminase (EC 3.5.4.26) is an enzyme that catalyzes the chemical reaction

2,5-diamino-6-hydroxy-4-(5-phosphoribosylamino)pyrimidine + H₂O ${\displaystyle \rightleftharpoons }$ 5-amino-6-(5-phosphoribosylamino)uracil + NH₃

Thus, the two substrates of this enzyme are 2,5-diamino-6-hydroxy-4-(5-phosphoribosylamino)pyrimidine and H₂O, whereas its two products are 5-amino-6-(5-phosphoribosylamino)uracil and NH₃.

This enzyme belongs to the family of hydrolases, those acting on carbon-nitrogen bonds other than peptide bonds (specifically in cyclic amidines). The systematic name of this enzyme class is 2,5-diamino-6-hydroxy-4-(5-phosphoribosylamino)pyrimidine 2-aminohydrolase. This enzyme participates in riboflavin metabolism.

Structural studies

As of late 2007, 6 structures have been solved for this class of enzymes, with PDB accession codes 2B3Z, 2D5N, 2G6V, 2HXV, 2O7P, and 2OBC.

References

• Burrows RB, Brown GM (1978). "Presence of Escherichia coli of a deaminase and a reductase involved in biosynthesis of riboflavin". J. Bacteriol. 136 (2): 657–67. doi:10.1128/JB.136.2.657-667.1978. PMC 218591. PMID 30756.

• Biology

• v
• t
• e

• EC 3.5.4
• Enzymes of known structure
• EC 3.5 stubs