1ya6
From Proteopedia
| Line 1: | Line 1: | ||
| - | [[Image:1ya6.gif|left|200px]] | + | [[Image:1ya6.gif|left|200px]] |
| - | + | ||
| - | '''alpha-glucosyltransferase in complex with UDP and a 13-mer DNA containing a central A:G mismatch''' | + | {{Structure |
| + | |PDB= 1ya6 |SIZE=350|CAPTION= <scene name='initialview01'>1ya6</scene>, resolution 2.4Å | ||
| + | |SITE= | ||
| + | |LIGAND= <scene name='pdbligand=NCO:COBALT+HEXAMMINE+ION'>NCO</scene> and <scene name='pdbligand=UDP:URIDINE-5'-DIPHOSPHATE'>UDP</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 in complex with UDP and a 13-mer DNA containing a central A:G mismatch''' | ||
| + | |||
==Overview== | ==Overview== | ||
| Line 7: | Line 16: | ||
==About this Structure== | ==About this Structure== | ||
| - | 1YA6 is a [ | + | 1YA6 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=1YA6 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]] | ||
| Line 21: | Line 30: | ||
[[Category: glycosyltransferase/dna]] | [[Category: glycosyltransferase/dna]] | ||
| - | ''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 15:20:15 2008'' |
Revision as of 13:20, 20 March 2008
| |||||||
| , resolution 2.4Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | and | ||||||
| Activity: | DNA alpha-glucosyltransferase, with EC number 2.4.1.26 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
alpha-glucosyltransferase in complex with UDP and a 13-mer DNA containing a central A:G mismatch
Overview
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 Structure
1YA6 is a Single protein structure of sequence from Bacteriophage t4. Full crystallographic information is available from OCA.
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:16081100
Page seeded by OCA on Thu Mar 20 15:20:15 2008
