Dataset Information

The unusual UBZ domain of Saccharomyces cerevisiae polymerase ?.

ABSTRACT: Recent research has revealed the presence of ubiquitin-binding domains in the Y family polymerases. The ubiquitin-binding zinc finger (UBZ) domain of human polymerase ? is vital for its regulation, localization, and function. Here, we elucidate structural and functional features of the non-canonical UBZ motif of Saccharomyces cerevisiae pol ?. Characterization of pol ? mutants confirms the importance of the UBZ motif and implies that its function is independent of zinc binding. Intriguingly, we demonstrate that zinc does bind to and affect the structure of the purified UBZ domain, but is not required for its ubiquitin-binding activity. Our finding that this unusual zinc finger is able to interact with ubiquitin even in its apo form adds support to the model that ubiquitin binding is the primary and functionally important activity of the UBZ domain in S. cerevisiae polymerase ?. Putative ubiquitin-binding domains, primarily UBZs, are identified in the majority of known pol ? homologs. We discuss the implications of our observations for zinc finger structure and pol ? regulation.

SUBMITTER: Woodruff RV

PROVIDER: S-EPMC2970701 | biostudies-literature | 2010 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

The unusual UBZ domain of Saccharomyces cerevisiae polymerase η.

Woodruff Rachel V RV Bomar Martha G MG D'Souza Sanjay S Zhou Pei P Walker Graham C GC

DNA repair 20100915 11

Recent research has revealed the presence of ubiquitin-binding domains in the Y family polymerases. The ubiquitin-binding zinc finger (UBZ) domain of human polymerase η is vital for its regulation, localization, and function. Here, we elucidate structural and functional features of the non-canonical UBZ motif of Saccharomyces cerevisiae pol η. Characterization of pol η mutants confirms the importance of the UBZ motif and implies that its function is independent of zinc binding. Intriguingly, we ...[more]

PMID: 20837403

Similar Datasets

Project description:Humans are exposed to N-nitroso compounds (NOCs) both endogenously and exogenously from a number of environmental sources, and NOCs are both mutagenic and carcinogenic. After metabolic activation, some NOCs can induce carboxymethylation of nucleobases through a diazoacetate intermediate, which could give rise to p53 mutations similar to those seen in human gastrointestinal cancers. It was previously found that the growth of polymerase ?-deficient human cells was inhibited by treatment with azaserine, a DNA carboxymethylation agent, suggesting the importance of this polymerase in bypassing the azaserine-induced carboxymethylated DNA lesions. In this study, we examined how carboxymethylated DNA lesions, which included N(6)-carboxymethyl-2'-deoxyadenosine (N(6)-CMdA), N(4)-carboxymethyl-2'-deoxycytidine (N(4)-CMdC), N3-carboxymethylthymidine (N3-CMdT), and O(4)-carboxymethylthymidine (O(4)-CMdT), perturbed the efficiency and fidelity of DNA replication mediated by Saccharomyces cerevisiae polymerase ? (pol ?). Our results from steady-state kinetic assay showed that pol ? could readily bypass and extend past N(6)-CMdA and incorporated the correct nucleotides opposite the lesion and its neighboring 5'-nucleoside with high efficiency. By contrast, the polymerase could bypass N(4)-CMdC inefficiently, with substantial misincorporation of dCMP followed by dAMP, though pol ? could extend past the lesion with high fidelity and efficiency when dGMP was incorporated opposite the lesion. On the other hand, yeast pol ? experienced great difficulty in bypassing O(4)-CMdT and N3-CMdT, and the polymerase inserted preferentially the incorrect dGMP opposite these two DNA lesions; the extension step, nevertheless, occurred with high fidelity and efficiency when the correct dAMP was opposite the lesion, as opposed to the preferentially incorporated incorrect dGMP. These results suggest that these lesions may contribute significantly to diazoacetate-induced mutations and those in the p53 gene observed in human gastrointestinal tumors.

Dataset Information

The unusual UBZ domain of Saccharomyces cerevisiae polymerase ?.

Publications

The unusual UBZ domain of Saccharomyces cerevisiae polymerase η.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets