• Source: Purine nucleosidase

In enzymology, a purine nucleosidase (EC 3.2.2.1) is an enzyme that catalyzes the chemical reaction

a purine nucleoside + H2O



⇌


{\displaystyle \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 1EZR, 1HOZ, 1HP0, 1KIC, 1KIE, 1MAS, 1R4F, 2C40, 2FF1, 2FF2, and 2MAS.




References



HEPPEL LA, HILMOE RJ (1952). "[Phosphorolysis and hydrolysis of purine ribosides by enzymes from yeast.]". J. Biol. Chem. 198 (2): 683–94. doi:10.1016/S0021-9258(18)55525-3. PMID 12999785.
Kalckar HM. "Biosynthetic aspects of nucleosides and nucleic acids". Pubbl. Staz. Zool. Napoli: 87–103.
Takagi Y, Horecker BL (1956). "Purification and properties of a bacterial riboside hydrolyase". J. Biol. Chem. 225 (1): 77–86. doi:10.1016/S0021-9258(18)64911-7. PMID 13416219.
Tarr HLA (1955). "Fish muscle riboside hydrolases". Biochem. J. 59 (3): 386–391. doi:10.1042/bj0590386. PMC 1216255. PMID 14363106.
Parkin DW (1996). "Purine-specific nucleoside N-ribohydrolase from Trypanosoma brucei brucei. Purification, specificity, and kinetic mechanism". J. Biol. Chem. 271 (36): 21713–9. doi:10.1074/jbc.271.36.21713. PMID 8702965.
S; Takeda, S; Xie, SX; Hatanaka, H; Ashikari, T; Amachi, T; Shimizu, S (2001). "Purification, characterization, and gene cloning of purine nucleosidase from Ochrobactrum anthropi". Appl. Environ. Microbiol. 67 (4): 1783–7. doi:10.1128/AEM.67.4.1783-1787.2001. PMC 92797. PMID 11282633.
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 (18): 15938–46. doi:10.1074/jbc.M111735200. PMID 11854281.
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 (21): 7805–17. doi:10.1021/bi047394h. PMID 15909995.

Kata Kunci Pencarian:

• Purine nucleosidase
• Ribosylpyrimidine nucleosidase
• Inosinate nucleosidase
• AMP nucleosidase
• Adenosine nucleosidase
• Inosine nucleosidase
• Nucleoside
• 5′-Methylthioadenosine
• Nucleic acid metabolism
• List of EC numbers (EC 3)