Structural basis for the suppression of skin cancers by DNA polymerase η

ABSTRACT The yeast RAD30-encoded DNA polymerase η (Polη) bypasses a cis-syn thymine-thymine dimer efficiently and accurately. Human DNA polymerase η functions similarly in the bypass of this lesion, and mutations in human Polη result in the cancer prone syndrome, the variant form of xeroderma pigmentosum. UV light, however, also elicits the formation ofcis-syn cyclobutane dimers and (6-4) photoproducts at 5′-CC-3′ and 5′-TC-3′ sites, and in both yeast and human DNA, UV-induced mutations occur primarily by 3′ C to T transitions. Genetic studies presented here reveal a role for yeast Polη in the error-free bypass of cyclobutane dimers and (6-4) photoproducts formed at CC and TC sites. Thus, by preventing UV mutagenesis at a wide spectrum of dipyrimidine sites, Polη plays a pivotal role in minimizing the incidence of sunlight-induced skin cancers in humans.

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Error-Prone Replication through UV Lesions by DNA Polymerase θ Protects against Skin Cancers

Cell ◽

10.1016/j.cell.2019.01.023 ◽

2019 ◽

Vol 176 (6) ◽

pp. 1295-1309.e15 ◽

Cited By ~ 25

Author(s):

Jung-Hoon Yoon ◽

Mark J. McArthur ◽

Jeseong Park ◽

Debashree Basu ◽

Maki Wakamiya ◽

...

Keyword(s):

Dna Polymerase ◽

Skin Cancers ◽

Uv Lesions

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Snapshots of a modified nucleotide moving through the confines of a DNA polymerase

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1811518115 ◽

2018 ◽

Vol 115 (40) ◽

pp. 9992-9997 ◽

Cited By ~ 16

Author(s):

Heike Maria Kropp ◽

Simon Leonard Dürr ◽

Christine Peter ◽

Kay Diederichs ◽

Andreas Marx

Keyword(s):

Dna Polymerase ◽

Dna Polymerases ◽

Ternary Complexes ◽

Structural Basis ◽

Modified Nucleotides ◽

Molecular Mechanics Calculations ◽

Modified Dna ◽

Substrate Properties ◽

Dna Strand ◽

Dna Substrate

DNA polymerases have evolved to process the four canonical nucleotides accurately. Nevertheless, these enzymes are also known to process modified nucleotides, which is the key to numerous core biotechnology applications. Processing of modified nucleotides includes incorporation of the modified nucleotide and postincorporation elongation to proceed with the synthesis of the nascent DNA strand. The structural basis for postincorporation elongation is currently unknown. We addressed this issue and successfully crystallized KlenTaq DNA polymerase in six closed ternary complexes containing the enzyme, the modified DNA substrate, and the incoming nucleotide. Each structure shows a high-resolution snapshot of the elongation of a modified primer, where the modification “moves” from the 3′-primer terminus upstream to the sixth nucleotide in the primer strand. Combining these data with quantum mechanics/molecular mechanics calculations and biochemical studies elucidates how the enzyme and the modified substrate mutually modulate their conformations without compromising the enzyme’s activity significantly. The study highlights the plasticity of the system as origin of the broad substrate properties of DNA polymerases and facilitates the design of improved systems.

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Family D DNA polymerase interacts with GINS to promote CMG-helicase in the archaeal replisome

Nucleic Acids Research ◽

10.1093/nar/gkab799 ◽

2021 ◽

Author(s):

Keisuke Oki ◽

Mariko Nagata ◽

Takeshi Yamagami ◽

Tomoyuki Numata ◽

Sonoko Ishino ◽

...

Keyword(s):

Crystal Structure ◽

Dna Polymerase ◽

Direct Interaction ◽

Crystal Structure Analysis ◽

Site Directed Mutagenesis ◽

Structural Basis ◽

Functional Connection ◽

Terminal Domain ◽

The Family ◽

Lagging Strand

Abstract Genomic DNA replication requires replisome assembly. We show here the molecular mechanism by which CMG (GAN–MCM–GINS)-like helicase cooperates with the family D DNA polymerase (PolD) in Thermococcus kodakarensis. The archaeal GINS contains two Gins51 subunits, the C-terminal domain of which (Gins51C) interacts with GAN. We discovered that Gins51C also interacts with the N-terminal domain of PolD’s DP1 subunit (DP1N) to connect two PolDs in GINS. The two replicases in the replisome should be responsible for leading- and lagging-strand synthesis, respectively. Crystal structure analysis of the DP1N–Gins51C–GAN ternary complex was provided to understand the structural basis of the connection between the helicase and DNA polymerase. Site-directed mutagenesis analysis supported the interaction mode obtained from the crystal structure. Furthermore, the assembly of helicase and replicase identified in this study is also conserved in Eukarya. PolD enhances the parental strand unwinding via stimulation of ATPase activity of the CMG-complex. This is the first evidence of the functional connection between replicase and helicase in Archaea. These results suggest that the direct interaction of PolD with CMG-helicase is critical for synchronizing strand unwinding and nascent strand synthesis and possibly provide a functional machinery for the effective progression of the replication fork.

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