1J39: Crystal Structure Of T4 Phage Bgt In Complex With Its Udp-Glucose Substrate

Citation:
Abstract
T4 phage beta-glucosyltransferase (BGT) is an inverting glycosyltransferase (GT) that transfers glucose from uridine diphospho-glucose (UDP-glucose) to an acceptor modified DNA. BGT belongs to the GT-B structural superfamily, represented, so far, by five different inverting or retaining GT families. Here, we report three high-resolution X-ray structures of BGT and a point mutant solved in the presence of UDP-glucose. The two co-crystal structures of the D100A mutant show that, unlike the wild-type enzyme, this mutation prevents glucose hydrolysis. This strongly indicates that Asp100 is the catalytic base. We obtained the wild-type BGT-UDP-glucose complex by soaking substrate-free BGT crystals. Comparison with a previous structure of BGT solved in the presence of the donor product UDP and an acceptor analogue provides the first model of an inverting GT-B enzyme in which both the donor and acceptor substrates are bound to the active site. The structural analyses support the in-line displacement reaction mechanism previously proposed, locate residues involved in donor substrate specificity and identify the catalytic base.
PDB ID: 1J39Download
MMDB ID: 24065
PDB Deposition Date: 2003/1/21
Updated in MMDB: 2007/10
Experimental Method:
x-ray diffraction
Resolution: 1.87  Å
Source Organism:
Similar Structures:
Biological Unit for 1J39: monomeric; determined by author
Molecular Components in 1J39
Label Count Molecule
Protein (1 molecule)
1
DNA Beta-glucosyltransferase(Gene symbol: b-gt)
Molecule annotation
Chemicals (4 molecules)
1
1
2
3
* Click molecule labels to explore molecular sequence information.

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