This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.
Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.
2bgu
From Proteopedia
CRYSTAL STRUCTURE OF THE DNA MODIFYING ENZYME BETA-GLUCOSYLTRANSFERASE IN THE PRESENCE AND ABSENCE OF THE SUBSTRATE URIDINE DIPHOSPHOGLUCOSE
Overview
Bacteriophage 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.
About this Structure
2BGU is a Single protein structure of sequence from Enterobacteria phage t4. Full crystallographic information is available from OCA.
Reference
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 Page seeded by OCA on Sat May 3 20:16:08 2008
