1xv5: Difference between revisions
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|PDB= 1xv5 |SIZE=350|CAPTION= <scene name='initialview01'>1xv5</scene>, resolution 1.73Å | |PDB= 1xv5 |SIZE=350|CAPTION= <scene name='initialview01'>1xv5</scene>, resolution 1.73Å | ||
|SITE= | |SITE= | ||
|LIGAND= <scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=UDP:URIDINE-5 | |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] | |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= | |GENE= | ||
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[[Category: transferase]] | [[Category: transferase]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 23 14:16:26 2008'' | ||
Revision as of 15:16, 23 March 2008
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| , resolution 1.73Å | |||||||
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| 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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