Catalog Home Page

Uracil DNA glycosylase (UDG) activities in Bradyrhizobium diazoefficiens: characterization of a new class of UDG with broad substrate specificity

Chembazhi, U.V., Patil, V.V., Sah, S., Reeve, W., Tiwari, R.P., Woo, E. and Varshney, U. (2017) Uracil DNA glycosylase (UDG) activities in Bradyrhizobium diazoefficiens: characterization of a new class of UDG with broad substrate specificity. Nucleic Acids Research, 45 (10). pp. 5863-5876.

[img]
Preview
PDF - Published Version
Available under License Creative Commons Attribution Non-commercial.

Download (6MB) | Preview
Free to read: https://doi.org/10.1093/nar/gkx209
*No subscription required

Abstract

Repair of uracils in DNA is initiated by uracil DNA glycosylases (UDGs). Family 1 UDGs (Ung) are the most efficient and ubiquitous proteins having an exquisite specificity for uracils in DNA. Ung are characterized by motifs A (GQDPY) and B (HPSPLS) sequences. We report a novel dimeric UDG, Blr0248 (BdiUng) from Bradyrhizobium diazoefficiens. Although BdiUng contains the motif A (GQDPA), it has low sequence identity to known UDGs. BdiUng prefers single stranded DNA and excises uracil, 5-hydroxymethyl-uracil or xanthine from it. BdiUng is impervious to inhibition by AP DNA, and Ugi protein that specifically inhibits family 1 UDGs. Crystal structure of BdiUng shows similarity with the family 4 UDGs in its overall fold but with family 1 UDGs in key active site residues. However, instead of a classical motif B, BdiUng has a uniquely extended protrusion explaining the lack of Ugi inhibition. Structural and mutational analyses of BdiUng have revealed the basis for the accommodation of diverse substrates into its substrate binding pocket. Phylogenetically, BdiUng belongs to a new UDG family. Bradyrhizobium diazoefficiens presents a unique scenario where the presence of at least four families of UDGs may compensate for the absence of an efficient family 1 homologue.

Publication Type: Journal Article
Murdoch Affiliation: School of Veterinary and Life Sciences
Centre for Rhizobium Studies
Publisher: Oxford University Press
Copyright: © 2017 Oxford University Press
URI: http://researchrepository.murdoch.edu.au/id/eprint/37402
Item Control Page Item Control Page

Downloads

Downloads per month over past year