1j39

From Proteopedia

Crystal Structure of T4 phage BGT in complex with its UDP-glucose substrate

PDB ID 1j39

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Structural highlights

1j39 is a 1 chain structure with sequence from Escherichia virus T4. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	X-ray diffraction, Resolution 1.87Å
Ligands:	,
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

GSTB_BPT4 Catalyzes the transfer of glucose (Glc) from uridine diphosphoglucose (UDP-Glc) to 5-hydroxymethylcytosine (5-HMC) in double-stranded DNA. Is involved in a DNA modification process to protect the phage genome against its own nucleases and the host restriction endonuclease system.

Publication Abstract from PubMed

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.

Crystal structures of the T4 phage beta-glucosyltransferase and the D100A mutant in complex with UDP-glucose: glucose binding and identification of the catalytic base for a direct displacement mechanism.,Lariviere L, Gueguen-Chaignon V, Morera S J Mol Biol. 2003 Jul 25;330(5):1077-86. PMID:12860129^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Lariviere L, Gueguen-Chaignon V, Morera S. Crystal structures of the T4 phage beta-glucosyltransferase and the D100A mutant in complex with UDP-glucose: glucose binding and identification of the catalytic base for a direct displacement mechanism. J Mol Biol. 2003 Jul 25;330(5):1077-86. PMID:12860129