1grv: Difference between revisions
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'''HYPOXANTHINE PHOSPHORIBOSYLTRANSFERASE FROM E. COLI''' | {{Structure | ||
|PDB= 1grv |SIZE=350|CAPTION= <scene name='initialview01'>1grv</scene>, resolution 2.9Å | |||
|SITE= <scene name='pdbsite=MGA:Mg+Binding+Site+For+Chain+B'>MGA</scene> | |||
|LIGAND= <scene name='pdbligand=MG:MAGNESIUM ION'>MG</scene> | |||
|ACTIVITY= [http://en.wikipedia.org/wiki/Hypoxanthine_phosphoribosyltransferase Hypoxanthine phosphoribosyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.4.2.8 2.4.2.8] | |||
|GENE= | |||
}} | |||
'''HYPOXANTHINE PHOSPHORIBOSYLTRANSFERASE FROM E. COLI''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
1GRV is a [ | 1GRV is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1GRV OCA]. | ||
==Reference== | ==Reference== | ||
Crystal structures of free, IMP-, and GMP-bound Escherichia coli hypoxanthine phosphoribosyltransferase., Guddat LW, Vos S, Martin JL, Keough DT, de Jersey J, Protein Sci. 2002 Jul;11(7):1626-38. PMID:[http:// | Crystal structures of free, IMP-, and GMP-bound Escherichia coli hypoxanthine phosphoribosyltransferase., Guddat LW, Vos S, Martin JL, Keough DT, de Jersey J, Protein Sci. 2002 Jul;11(7):1626-38. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/12070315 12070315] | ||
[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Hypoxanthine phosphoribosyltransferase]] | [[Category: Hypoxanthine phosphoribosyltransferase]] | ||
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[[Category: transferase]] | [[Category: transferase]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 11:27:05 2008'' | ||
Revision as of 12:27, 20 March 2008
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| , resolution 2.9Å | |||||||
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| Sites: | |||||||
| Ligands: | |||||||
| Activity: | Hypoxanthine phosphoribosyltransferase, with EC number 2.4.2.8 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
HYPOXANTHINE PHOSPHORIBOSYLTRANSFERASE FROM E. COLI
OverviewOverview
Crystal structures have been determined for free Escherichia coli hypoxanthine phosphoribosyltransferase (HPRT) (2.9 A resolution) and for the enzyme in complex with the reaction products, inosine 5'-monophosphate (IMP) and guanosine 5'-monophosphate (GMP) (2.8 A resolution). Of the known 6-oxopurine phosphoribosyltransferase (PRTase) structures, E. coli HPRT is most similar in structure to that of Tritrichomonas foetus HGXPRT, with a rmsd for 150 Calpha atoms of 1.0 A. Comparison of the free and product bound structures shows that the side chain of Phe156 and the polypeptide backbone in this vicinity move to bind IMP or GMP. A nonproline cis peptide bond, also found in some other 6-oxopurine PRTases, is observed between Leu46 and Arg47 in both the free and complexed structures. For catalysis to occur, the 6-oxopurine PRTases have a requirement for divalent metal ion, usually Mg(2+) in vivo. In the free structure, a Mg(2+) is coordinated to the side chains of Glu103 and Asp104. This interaction may be important for stabilization of the enzyme before catalysis. E. coli HPRT is unique among the known 6-oxopurine PRTases in that it exhibits a marked preference for hypoxanthine as substrate over both xanthine and guanine. The structures suggest that its substrate specificity is due to the modes of binding of the bases. In E. coli HPRT, the carbonyl oxygen of Asp163 would likely form a hydrogen bond with the 2-exocyclic nitrogen of guanine (in the HPRT-guanine-PRib-PP-Mg(2+) complex). However, hypoxanthine does not have a 2-exocyclic atom and the HPRT-IMP structure suggests that hypoxanthine is likely to occupy a different position in the purine-binding pocket.
About this StructureAbout this Structure
1GRV is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
ReferenceReference
Crystal structures of free, IMP-, and GMP-bound Escherichia coli hypoxanthine phosphoribosyltransferase., Guddat LW, Vos S, Martin JL, Keough DT, de Jersey J, Protein Sci. 2002 Jul;11(7):1626-38. PMID:12070315
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