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1l1r
From Proteopedia
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| - | [[Image:1l1r.jpg|left|200px]] | + | [[Image:1l1r.jpg|left|200px]] |
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| - | '''Crystal Structure of APRTase from Giardia lamblia Complexed with 9-deazaadenine, Mg2+ and PRPP''' | + | {{Structure |
| + | |PDB= 1l1r |SIZE=350|CAPTION= <scene name='initialview01'>1l1r</scene>, resolution 1.95Å | ||
| + | |SITE= | ||
| + | |LIGAND= <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=9DA:9-DEAZAADENINE'>9DA</scene> and <scene name='pdbligand=PRP:ALPHA-PHOSPHORIBOSYLPYROPHOSPHORIC ACID'>PRP</scene> | ||
| + | |ACTIVITY= [http://en.wikipedia.org/wiki/Adenine_phosphoribosyltransferase Adenine phosphoribosyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.4.2.7 2.4.2.7] | ||
| + | |GENE= | ||
| + | }} | ||
| + | |||
| + | '''Crystal Structure of APRTase from Giardia lamblia Complexed with 9-deazaadenine, Mg2+ and PRPP''' | ||
| + | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
| - | 1L1R is a [ | + | 1L1R is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Giardia_intestinalis Giardia intestinalis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1L1R OCA]. |
==Reference== | ==Reference== | ||
| - | Closed site complexes of adenine phosphoribosyltransferase from Giardia lamblia reveal a mechanism of ribosyl migration., Shi W, Sarver AE, Wang CC, Tanaka KS, Almo SC, Schramm VL, J Biol Chem. 2002 Oct 18;277(42):39981-8. Epub 2002 Aug 8. PMID:[http:// | + | Closed site complexes of adenine phosphoribosyltransferase from Giardia lamblia reveal a mechanism of ribosyl migration., Shi W, Sarver AE, Wang CC, Tanaka KS, Almo SC, Schramm VL, J Biol Chem. 2002 Oct 18;277(42):39981-8. Epub 2002 Aug 8. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/12171925 12171925] |
[[Category: Adenine phosphoribosyltransferase]] | [[Category: Adenine phosphoribosyltransferase]] | ||
[[Category: Giardia intestinalis]] | [[Category: Giardia intestinalis]] | ||
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[[Category: purine metabolism]] | [[Category: purine metabolism]] | ||
| - | ''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 12:25:08 2008'' |
Revision as of 10:25, 20 March 2008
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| , resolution 1.95Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , and | ||||||
| Activity: | Adenine phosphoribosyltransferase, with EC number 2.4.2.7 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Crystal Structure of APRTase from Giardia lamblia Complexed with 9-deazaadenine, Mg2+ and PRPP
Overview
The adenine phosphoribosyltransferase (APRTase) from Giardia lamblia was co-crystallized with 9-deazaadenine and sulfate or with 9-deazaadenine and Mg-phosphoribosylpyrophosphate. The complexes were solved and refined to 1.85 and 1.95 A resolution. Giardia APRTase is a symmetric homodimer with the monomers built around Rossman fold cores, an element common to all known purine phosphoribosyltransferases. The catalytic sites are capped with a small hood domain that is unique to the APRTases. These structures reveal several features relevant to the catalytic function of APRTase: 1) a non-proline cis peptide bond (Glu(61)-Ser(62)) is required to form the pyrophosphate binding site in the APRTase.9dA.MgPRPP complex but is a trans peptide bond in the absence of pyrophosphate group, as observed in the APRTase.9dA.SO4 complex; 2) a catalytic site loop is closed and fully ordered in both complexes, with Glu(100) from the catalytic loop acting as the acid/base for protonation/deprotonation of N-7 of the adenine ring; 3) the pyrophosphoryl charge is neutralized by a single Mg2+ ion and Arg(63), in contrast to the hypoxanthine-guanine phosphoribosyltransferases, which use two Mg2+ ions; and 4) the nearest structural neighbors to APRTases are the orotate phosphoribosyltransferases, suggesting different paths of evolution for adenine relative to other purine PRTases. An overlap comparison of AMP and 9-deazaadenine plus Mg-PRPP at the catalytic sites of APRTases indicated that reaction coordinate motion involves a 2.1-A excursion of the ribosyl anomeric carbon, whereas the adenine ring and the 5-phosphoryl group remained fixed. G. lamblia APRTase therefore provides another example of nucleophilic displacement by electrophile migration.
About this Structure
1L1R is a Single protein structure of sequence from Giardia intestinalis. Full crystallographic information is available from OCA.
Reference
Closed site complexes of adenine phosphoribosyltransferase from Giardia lamblia reveal a mechanism of ribosyl migration., Shi W, Sarver AE, Wang CC, Tanaka KS, Almo SC, Schramm VL, J Biol Chem. 2002 Oct 18;277(42):39981-8. Epub 2002 Aug 8. PMID:12171925
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