Purine nucleosidase explained

purine nucleosidase
Ec Number:	3.2.2.1
Cas Number:	9025-44-9
Go Code:	0008477
Width:	270

In enzymology, a purine nucleosidase is an enzyme that catalyzes the chemical reaction

a purine nucleoside + H₂O

\rightleftharpoons D-ribose + a purine base

Thus, the two substrates of this enzyme are purine nucleoside and H₂O, whereas its two products are D-ribose and purine base.

This enzyme belongs to the family of hydrolases, specifically those glycosylases that hydrolyse N-glycosyl compounds. The systematic name of this enzyme class is purine-nucleoside ribohydrolase. Other names in common use include nucleosidase, purine beta-ribosidase, purine nucleoside hydrolase, purine ribonucleosidase, ribonucleoside hydrolase, nucleoside hydrolase, N-ribosyl purine ribohydrolase, nucleosidase g, N-D-ribosylpurine ribohydrolase, inosine-adenosine-guanosine preferring nucleoside hydrolase, purine-specific nucleoside N-ribohydrolase, IAG-nucleoside hydrolase, and IAG-NH. This enzyme participates in purine metabolism and nicotinate and nicotinamide metabolism.

Structural studies

As of late 2007, 11 structures have been solved for this class of enzymes, with PDB accession codes,,,,,,,,,, and .

References

• HEPPEL LA, HILMOE RJ . 1952 . [Phosphorolysis and hydrolysis of purine ribosides by enzymes from yeast.] . J. Biol. Chem. . 198 . 683 - 94 . 12999785 . 2 .
• Kalckar HM . Napoli . Biosynthetic aspects of nucleosides and nucleic acids . Pubbl. Staz. . Zool. . 87 - 103 .
• Takagi Y, Horecker BL. 1956 . Purification and properties of a bacterial riboside hydrolyase . J. Biol. Chem. . 225 . 77 - 86 . 13416219 . 1.
• Tarr HLA . 1955 . Fish muscle riboside hydrolases . Biochem. J. . 59 . 3 . 386 - 391 . 10.1042/bj0590386 . 14363106 . 1216255 .
• Parkin DW . 1996 . Purine-specific nucleoside N-ribohydrolase from Trypanosoma brucei brucei. Purification, specificity, and kinetic mechanism . J. Biol. Chem. . 271 . 21713 - 9 . 8702965 . 36 . 10.1074/jbc.271.36.21713. free .
• S . 2001 . Purification, characterization, and gene cloning of purine nucleosidase from Ochrobactrum anthropi . Appl. Environ. Microbiol. . 67 . 1783 - 7 . 11282633 . 10.1128/AEM.67.4.1783-1787.2001 . Takeda . S . Xie . SX . Hatanaka . H . Ashikari . T . Amachi . T . Shimizu . S . 4 . 92797 .
• Versees W, Decanniere K, Van Holsbeke E, Devroede N, Steyaert J . 2002 . Enzyme-substrate interactions in the purine-specific nucleoside hydrolase from Trypanosoma vivax . J. Biol. Chem. . 277 . 15938 - 46 . 11854281 . 10.1074/jbc.M111735200 . 18 . free .
• Mazumder-Shivakumar D, Bruice TC . 2005 . Computational study of IAG-nucleoside hydrolase: determination of the preferred ground state conformation and the role of active site residues . Biochemistry . 44 . 7805 - 17 . 15909995 . 10.1021/bi047394h . 21 .