This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.
Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.
1dbr
From Proteopedia
| Line 1: | Line 1: | ||
[[Image:1dbr.jpg|left|200px]] | [[Image:1dbr.jpg|left|200px]] | ||
| - | + | <!-- | |
| - | + | The line below this paragraph, containing "STRUCTURE_1dbr", creates the "Structure Box" on the page. | |
| - | + | You may change the PDB parameter (which sets the PDB file loaded into the applet) | |
| - | + | or the SCENE parameter (which sets the initial scene displayed when the page is loaded), | |
| - | | | + | or leave the SCENE parameter empty for the default display. |
| - | | | + | --> |
| - | + | {{STRUCTURE_1dbr| PDB=1dbr | SCENE= }} | |
| - | + | ||
| - | + | ||
| - | }} | + | |
'''HYPOXANTHINE GUANINE XANTHINE''' | '''HYPOXANTHINE GUANINE XANTHINE''' | ||
| Line 30: | Line 27: | ||
[[Category: Schumacher, M A.]] | [[Category: Schumacher, M A.]] | ||
[[Category: Ullman, B.]] | [[Category: Ullman, B.]] | ||
| - | [[Category: | + | [[Category: Glycosyltransferase]] |
| - | [[Category: | + | [[Category: Purine salvage]] |
| - | [[Category: | + | [[Category: Transferase]] |
| - | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 13:40:00 2008'' | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | |
Revision as of 10:40, 2 May 2008
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. 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 Fri May 2 13:40:00 2008
