1nul
From Proteopedia
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| - | [[Image:1nul.gif|left|200px]] | + | [[Image:1nul.gif|left|200px]] |
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| - | '''XPRTASE FROM E. COLI''' | + | {{Structure |
| + | |PDB= 1nul |SIZE=350|CAPTION= <scene name='initialview01'>1nul</scene>, resolution 1.80Å | ||
| + | |SITE= | ||
| + | |LIGAND= <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene> and <scene name='pdbligand=MG:MAGNESIUM ION'>MG</scene> | ||
| + | |ACTIVITY= [http://en.wikipedia.org/wiki/Xanthine_phosphoribosyltransferase Xanthine phosphoribosyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.4.2.22 2.4.2.22] | ||
| + | |GENE= | ||
| + | }} | ||
| + | |||
| + | '''XPRTASE FROM E. COLI''' | ||
| + | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
| - | 1NUL is a [ | + | 1NUL 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=1NUL OCA]. |
==Reference== | ==Reference== | ||
| - | Crystal structure of Escherichia coli xanthine phosphoribosyltransferase., Vos S, de Jersey J, Martin JL, Biochemistry. 1997 Apr 8;36(14):4125-34. PMID:[http:// | + | Crystal structure of Escherichia coli xanthine phosphoribosyltransferase., Vos S, de Jersey J, Martin JL, Biochemistry. 1997 Apr 8;36(14):4125-34. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/9100006 9100006] |
[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
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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 13:01:53 2008'' |
Revision as of 11:01, 20 March 2008
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| , resolution 1.80Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | and | ||||||
| Activity: | Xanthine phosphoribosyltransferase, with EC number 2.4.2.22 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
XPRTASE FROM E. COLI
Overview
Xanthine phosphoribosyltransferase (XPRT; EC 2.4.2.22) from Escherichia coli is a tetrameric enzyme having 152 residues per subunit. XPRT catalyzes the transfer of the phosphoribosyl group from 5-phospho-alpha-D-ribosyl 1-pyrophosphate (PRib-PP) to the 6-oxopurine bases guanine, xanthine, and hypoxanthine to form GMP, XMP, and IMP, respectively. Crystals grown in the absence of substrate or product were used to determine the structure of XPRT at a resolution of 1.8 A, by multiple isomorphous replacement. The core structure of XPRT includes a five-stranded parallel beta-sheet surrounded by three alpha-helices, which is similar to that observed in other known phosphoribosyltransferase (PRTase) structures. The XPRT structure also has several interesting features. A glutamine residue in the purine binding site may be responsible for the altered 6-oxopurine base specificity seen in this enzyme compared to other 6-oxopurine PRTases. Also, we observe both a magnesium ion and a sulfate ion bound at the PRib-PP binding site of XPRT. The sulfate ion interacts with Arg-37 which has a cis-peptide conformation, and the magnesium ion interacts with Asp-89, a highly conserved acidic residue in the PRib-PP binding site motif. The XPRT structure also incorporates a feature which has not been observed in other PRTase structures. The C-terminal 12 residues of XPRT adopt an unusual extended conformation and make interactions with a neighboring subunit. The very last residue, Arg-152, could form part of the active site of a symmetry-related subunit in the XPRT tetramer.
About this Structure
1NUL is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
Crystal structure of Escherichia coli xanthine phosphoribosyltransferase., Vos S, de Jersey J, Martin JL, Biochemistry. 1997 Apr 8;36(14):4125-34. PMID:9100006
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