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1dbr
From Proteopedia
(New page: 200px<br /><applet load="1dbr" size="450" color="white" frame="true" align="right" spinBox="true" caption="1dbr, resolution 2.4Å" /> '''HYPOXANTHINE GUANINE ...) |
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| - | [[Image:1dbr.jpg|left|200px]]<br /><applet load="1dbr" size=" | + | [[Image:1dbr.jpg|left|200px]]<br /><applet load="1dbr" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1dbr, resolution 2.4Å" /> | caption="1dbr, resolution 2.4Å" /> | ||
'''HYPOXANTHINE GUANINE XANTHINE'''<br /> | '''HYPOXANTHINE GUANINE XANTHINE'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Crystal structures of substrate-free and XMP-soaked | + | Crystal structures of substrate-free and XMP-soaked hypoxanthine-guanine-xanthine phosphoribosyltransferase (HGXPRTase) of the opportunistic pathogen Toxoplasma gondii have been determined to 2.4 and 2.9 A resolution, respectively. HGXPRTase displays the conserved PRTase fold. In the structure of the enzyme bound to its product, a long flexible loop (residues 115-126) is located away from the active site. Comparison to the substrate-free structure reveals a striking relocation of the loop, which is poised to cover the catalytic pocket, thus providing a mechanism by which the HG(X)PRTases shield their oxocarbonium transition states from nucleophilic attack by the bulk solvent. The conserved Ser 117-Tyr 118 dipeptide within the loop is brought to the active site, completing the ensemble of catalytic residues. |
==About this Structure== | ==About this Structure== | ||
| - | 1DBR is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Toxoplasma_gondii Toxoplasma gondii] with MG as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 1DBR is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Toxoplasma_gondii Toxoplasma gondii] with <scene name='pdbligand=MG:'>MG</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1DBR OCA]. |
==Reference== | ==Reference== | ||
| Line 13: | Line 13: | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Toxoplasma gondii]] | [[Category: Toxoplasma gondii]] | ||
| - | [[Category: Brennan, R | + | [[Category: Brennan, R G.]] |
[[Category: Carter, D.]] | [[Category: Carter, D.]] | ||
[[Category: Roos, D.]] | [[Category: Roos, D.]] | ||
| - | [[Category: Schumacher, M | + | [[Category: Schumacher, M A.]] |
[[Category: Ullman, B.]] | [[Category: Ullman, B.]] | ||
[[Category: MG]] | [[Category: MG]] | ||
| Line 23: | Line 23: | ||
[[Category: transferase]] | [[Category: transferase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:14:58 2008'' |
Revision as of 10:15, 21 February 2008
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HYPOXANTHINE GUANINE XANTHINE
Overview
Crystal structures of substrate-free and XMP-soaked hypoxanthine-guanine-xanthine phosphoribosyltransferase (HGXPRTase) of the opportunistic pathogen Toxoplasma gondii have been determined to 2.4 and 2.9 A resolution, respectively. HGXPRTase displays the conserved PRTase fold. In the structure of the enzyme bound to its product, a long flexible loop (residues 115-126) is located away from the active site. Comparison to the substrate-free structure reveals a striking relocation of the loop, which is poised to cover the catalytic pocket, thus providing a mechanism by which the HG(X)PRTases shield their oxocarbonium transition states from nucleophilic attack by the bulk solvent. The conserved Ser 117-Tyr 118 dipeptide within the loop is brought to the active site, completing the ensemble of catalytic residues.
About this Structure
1DBR is a Single protein structure of sequence from Toxoplasma gondii with as ligand. Full crystallographic information is available from OCA.
Reference
Crystal structures of Toxoplasma gondii HGXPRTase reveal the catalytic role of a long flexible loop., Schumacher MA, Carter D, Ross DS, Ullman B, Brennan RG, Nat Struct Biol. 1996 Oct;3(10):881-7. PMID:8836106
Page seeded by OCA on Thu Feb 21 12:14:58 2008
