1xv5: Difference between revisions
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[[Image:1xv5.gif|left|200px]] | [[Image:1xv5.gif|left|200px]] | ||
'''alpha-glucosyltransferase (AGT) in complex with UDP''' | {{Structure | ||
|PDB= 1xv5 |SIZE=350|CAPTION= <scene name='initialview01'>1xv5</scene>, resolution 1.73Å | |||
|SITE= | |||
|LIGAND= <scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=UDP:URIDINE-5'-DIPHOSPHATE'>UDP</scene>, <scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene> and <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene> | |||
|ACTIVITY= [http://en.wikipedia.org/wiki/DNA_alpha-glucosyltransferase DNA alpha-glucosyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.4.1.26 2.4.1.26] | |||
|GENE= | |||
}} | |||
'''alpha-glucosyltransferase (AGT) in complex with UDP''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
1XV5 is a [ | 1XV5 is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Bacteriophage_t4 Bacteriophage t4]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1XV5 OCA]. | ||
==Reference== | ==Reference== | ||
Structural evidence of a passive base-flipping mechanism for AGT, an unusual GT-B glycosyltransferase., Lariviere L, Sommer N, Morera S, J Mol Biol. 2005 Sep 9;352(1):139-50. PMID:[http:// | Structural evidence of a passive base-flipping mechanism for AGT, an unusual GT-B glycosyltransferase., Lariviere L, Sommer N, Morera S, J Mol Biol. 2005 Sep 9;352(1):139-50. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/16081100 16081100] | ||
[[Category: Bacteriophage t4]] | [[Category: Bacteriophage t4]] | ||
[[Category: DNA alpha-glucosyltransferase]] | [[Category: DNA alpha-glucosyltransferase]] | ||
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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 15:14:54 2008'' | ||
Revision as of 16:14, 20 March 2008
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| , resolution 1.73Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , , and | ||||||
| Activity: | DNA alpha-glucosyltransferase, with EC number 2.4.1.26 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
alpha-glucosyltransferase (AGT) in complex with UDP
OverviewOverview
The Escherichia coli T4 bacteriophage uses two glycosyltransferases to glucosylate and thus protect its DNA: the retaining alpha-glucosyltransferase (AGT) and the inverting beta-glucosyltransferase (BGT). They glucosylate 5-hydroxymethyl cytosine (5-HMC) bases of duplex DNA using UDP-glucose as the sugar donor to form an alpha-glucosidic linkage and a beta-glucosidic linkage, respectively. Five structures of AGT have been determined: a binary complex with the UDP product and four ternary complexes with UDP or UDP-glucose and oligonucleotides containing an A:G, HMU:G (hydroxymethyl uracyl) or AP:G (apurinic/apyrimidinic) mismatch at the target base-pair. AGT adopts the GT-B fold, one of the two folds known for GTs. However, while the sugar donor binding mode is classical for a GT-B enzyme, the sugar acceptor binding mode is unexpected and breaks the established consensus: AGT is the first GT-B enzyme that predominantly binds both the sugar donor and acceptor to the C-terminal domain. Its active site pocket is highly similar to four retaining GT-B glycosyltransferases (trehalose-6-phosphate synthase, glycogen synthase, glycogen and maltodextrin phosphorylases) strongly suggesting a common evolutionary origin and catalytic mechanism for these enzymes. Structure-guided mutagenesis and kinetic analysis do not permit identification of a nucleophile residue responsible for a glycosyl-enzyme intermediate for the classical double displacement mechanism. Interestingly, the DNA structures reveal partially flipped-out bases. They provide evidence for a passive role of AGT in the base-flipping mechanism and for its specific recognition of the acceptor base.
About this StructureAbout this Structure
1XV5 is a Single protein structure of sequence from Bacteriophage t4. Full crystallographic information is available from OCA.
ReferenceReference
Structural evidence of a passive base-flipping mechanism for AGT, an unusual GT-B glycosyltransferase., Lariviere L, Sommer N, Morera S, J Mol Biol. 2005 Sep 9;352(1):139-50. PMID:16081100
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