1jiv
T4 phage BGT in complex with Mg2+ : Form II
|
OverviewOverview
beta-Glucosyltransferase (BGT) is a DNA-modifying enzyme encoded by, bacteriophage T4 that transfers glucose from uridine diphosphoglucose to, 5-hydroxymethyl cytosine bases of phage T4 DNA. We report six X-ray, structures of the substrate-free and the UDP-bound enzyme. Four also, contain metal ions which activate the enzyme, including Mg(2+) in forms 1, and 2 and Mn(2+) or Ca(2+). The substrate-free BGT structure differs by a, domain movement from one previously determined in another space group., Further domain movements are seen in the complex with UDP and the four, UDP-metal complexes. Mg(2+), Mn(2+) and Ca(2+) bind near the, beta-phosphate of the nucleotide, but they occupy slightly different, positions and have different ligands depending on the metal and the, crystal form. Whilst the metal site observed in these complexes with the, product UDP is not compatible with a role in activating glucose transfer, it approximates the position of the positive charge in the oxocarbonium, ion thought to form on the glucose moiety of the substrate during, catalysis.
About this StructureAbout this Structure
1JIV is a Single protein structure of sequence from Bacteriophage t4 with MG and UDP as ligands. Active as DNA beta-glucosyltransferase, with EC number 2.4.1.27 Full crystallographic information is available from OCA.
ReferenceReference
High resolution crystal structures of T4 phage beta-glucosyltransferase: induced fit and effect of substrate and metal binding., Morera S, Lariviere L, Kurzeck J, Aschke-Sonnenborn U, Freemont PS, Janin J, Ruger W, J Mol Biol. 2001 Aug 17;311(3):569-77. PMID:11493010
Page seeded by OCA on Tue Nov 20 18:18:16 2007