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CRYSTAL STRUCTURE OF THE DNA MODIFYING ENZYME BETA-GLUCOSYLTRANSFERASE IN THE PRESENCE AND ABSENCE OF THE SUBSTRATE URIDINE DIPHOSPHOGLUCOSECRYSTAL STRUCTURE OF THE DNA MODIFYING ENZYME BETA-GLUCOSYLTRANSFERASE IN THE PRESENCE AND ABSENCE OF THE SUBSTRATE URIDINE DIPHOSPHOGLUCOSE
Structural highlights
FunctionGSTB_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 PubMedBacteriophage T4 beta-glucosyltransferase (EC 2.4.1.27) catalyses the transfer of glucose from uridine diphosphoglucose to hydroxymethyl groups of modified cytosine bases in T4 duplex DNA forming beta-glycosidic linkages. The enzyme forms part of a phage DNA protection system. We have solved and refined the crystal structure of recombinant beta-glucosyltransferase to 2.2 A resolution in the presence and absence of the substrate, uridine diphosphoglucose. The structure comprises two domains of similar topology, each reminiscent of a nucleotide binding fold. The two domains are separated by a central cleft which generates a concave surface along one side of the molecule. The substrate-bound complex reveals only clear electron density for the uridine diphosphate portion of the substrate. The UDPG is bound in a pocket at the bottom of the cleft between the two domains and makes extensive hydrogen bonding contacts with residues of the C-terminal domain only. The domains undergo a rigid body conformational change causing the structure to adopt a more closed conformation upon ligand binding. The movement of the domains is facilitated by a hinge region between residues 166 and 172. Electrostatic surface potential calculations reveal a large positive potential along the concave surface of the structure, suggesting a possible site for duplex DNA interaction. Crystal structure of the DNA modifying enzyme beta-glucosyltransferase in the presence and absence of the substrate uridine diphosphoglucose.,Vrielink A, Ruger W, Driessen HP, Freemont PS EMBO J. 1994 Aug 1;13(15):3413-22. PMID:8062817[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References |
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