1y6f: Difference between revisions
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[[ | ==alpha-glucosyltransferase in complex with UDP-glucose and DNA containing an abasic site== | ||
<StructureSection load='1y6f' size='340' side='right' caption='[[1y6f]], [[Resolution|resolution]] 2.40Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[1y6f]] is a 4 chain structure with sequence from [http://en.wikipedia.org/wiki/Enterobacteria_phage_t4 Enterobacteria phage t4]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1Y6F OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1Y6F FirstGlance]. <br> | |||
</td></tr><tr><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=PEG:DI(HYDROXYETHYL)ETHER'>PEG</scene>, <scene name='pdbligand=UDP:URIDINE-5-DIPHOSPHATE'>UDP</scene>, <scene name='pdbligand=UPG:URIDINE-5-DIPHOSPHATE-GLUCOSE'>UPG</scene><br> | |||
<tr><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=3DR:1,2-DIDEOXYRIBOFURANOSE-5-PHOSPHATE'>3DR</scene></td></tr> | |||
<tr><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1xv5|1xv5]], [[1y6g|1y6g]], [[1y8z|1y8z]], [[1ya6|1ya6]]</td></tr> | |||
<tr><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[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] </span></td></tr> | |||
<tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1y6f FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1y6f OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1y6f RCSB], [http://www.ebi.ac.uk/pdbsum/1y6f PDBsum]</span></td></tr> | |||
<table> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
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. | |||
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<ref>PMID:16081100</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
== | |||
< | |||
[[Category: DNA alpha-glucosyltransferase]] | [[Category: DNA alpha-glucosyltransferase]] | ||
[[Category: Enterobacteria phage t4]] | [[Category: Enterobacteria phage t4]] | ||
