scholarly journals The point mutations in the fingers domain increase the fidelity of DNA synthesis on undamaged DNA and abrogate DNA translesion synthesis in Y-family of DNA polymerases

2018 ◽  
pp. 11-11
Keyword(s):  
Dna Synthesis ◽  
Dna Polymerases ◽  
Point Mutations ◽  
Translesion Synthesis ◽  
Y Family

scholarly journals Beyond the Lesion: Back to High Fidelity DNA Synthesis

2022 ◽  
Vol 8 ◽  
Author(s):  
Joseph D. Kaszubowski ◽  
Michael A. Trakselis
Keyword(s):  
Dna Damage ◽  
Dna Synthesis ◽  
Dna Polymerases ◽  
Translesion Synthesis ◽  
Structural Features ◽  
Dna Bases ◽  
High Fidelity ◽  
Nucleotide Incorporation ◽  
Hand Off ◽  
Enzymatic Mechanisms

High fidelity (HiFi) DNA polymerases (Pols) perform the bulk of DNA synthesis required to duplicate genomes in all forms of life. Their structural features, enzymatic mechanisms, and inherent properties are well-described over several decades of research. HiFi Pols are so accurate that they become stalled at sites of DNA damage or lesions that are not one of the four canonical DNA bases. Once stalled, the replisome becomes compromised and vulnerable to further DNA damage. One mechanism to relieve stalling is to recruit a translesion synthesis (TLS) Pol to rapidly synthesize over and past the damage. These TLS Pols have good specificities for the lesion but are less accurate when synthesizing opposite undamaged DNA, and so, mechanisms are needed to limit TLS Pol synthesis and recruit back a HiFi Pol to reestablish the replisome. The overall TLS process can be complicated with several cellular Pols, multifaceted protein contacts, and variable nucleotide incorporation kinetics all contributing to several discrete substitution (or template hand-off) steps. In this review, we highlight the mechanistic differences between distributive equilibrium exchange events and concerted contact-dependent switching by DNA Pols for insertion, extension, and resumption of high-fidelity synthesis beyond the lesion.

scholarly journals Translesion Synthesis across Abasic Lesions by Human B-Family and Y-Family DNA Polymerases α, δ, η, ι, κ, and REV1

2010 ◽  
Vol 404 (1) ◽  
pp. 34-44 ◽  
Author(s):  
Jeong-Yun Choi ◽  
Seonhee Lim ◽  
Eun-Jin Kim ◽  
Ara Jo ◽  
F. Peter Guengerich
Keyword(s):  
Dna Polymerases ◽  
Translesion Synthesis ◽  
Y Family

scholarly journals Implications of inhibition of Rev1 interaction with Y family DNA polymerases for cisplatin chemotherapy

2021 ◽  
Author(s):  
Jung-Hoon Yoon ◽  
Robert E. Johnson ◽  
Louise Prakash ◽  
Satya Prakash
Keyword(s):  
Adverse Effects ◽  
Cancer Cells ◽  
Dna Polymerases ◽  
Translesion Synthesis ◽  
Dna Adduct ◽  
Secondary Malignancies ◽  
Normal Cells ◽  
Cross Links ◽  
Y Family

Chemotherapy with cisplatin becomes limiting due to toxicity and secondary malignancies. In principle, therapeutics could be improved by targeting translesion synthesis (TLS) polymerases (Pols) that promote replication through intrastrand cross-links, the major cisplatin-induced DNA adduct. However, to specifically target malignancies with minimal adverse effects on normal cells, a good understanding of TLS mechanisms in normal versus cancer cells is paramount. We show that in normal cells, TLS through cisplatin intrastrand cross-links is promoted by Polη- or Polι-dependent pathways, both of which require Rev1 as a scaffolding component. In contrast, cancer cells require Rev1-Polζ. Our findings that a recently identified Rev1 inhibitor, JH-RE-06, purported to specifically disrupt Rev1 interaction with Polζ to block TLS through cisplatin adducts in cancer cells, abrogates Rev1's ability to function with Y family Pols as well, implying that by inactivating Rev1-dependent TLS in normal cells, this inhibitor will exacerbate the toxicity and tumorigenicity of chemotherapeutics with cisplatin.

scholarly journals Enzymatic Switching Between Archaeal DNA Polymerases Facilitates Abasic Site Bypass

2021 ◽  
Vol 12 ◽  
Author(s):  
Xu Feng ◽  
Baochang Zhang ◽  
Ruyi Xu ◽  
Zhe Gao ◽  
Xiaotong Liu ◽  
...  
Keyword(s):  
Dna Synthesis ◽  
Enzyme Kinetics ◽  
Dna Polymerases ◽  
Dna Lesions ◽  
Abasic Site ◽  
Lesion Bypass ◽  
Translesion Dna Synthesis ◽  
Kinetics Studies ◽  
Abasic Sites ◽  
Y Family

Abasic sites are among the most abundant DNA lesions encountered by cells. Their replication requires actions of specialized DNA polymerases. Herein, two archaeal specialized DNA polymerases were examined for their capability to perform translesion DNA synthesis (TLS) on the lesion, including Sulfolobuss islandicus Dpo2 of B-family, and Dpo4 of Y-family. We found neither Dpo2 nor Dpo4 is efficient to complete abasic sites bypass alone, but their sequential actions promote lesion bypass. Enzyme kinetics studies further revealed that the Dpo4’s activity is significantly inhibited at +1 to +3 site past the lesion, at which Dpo2 efficiently extends the primer termini. Furthermore, their activities are inhibited upon synthesis of 5–6 nt TLS patches. Once handed over to Dpo1, these substrates basically inactivate its exonuclease, enabling the transition from proofreading to polymerization of the replicase. Collectively, by functioning as an “extender” to catalyze further DNA synthesis past the lesion, Dpo2 bridges the activity gap between Dpo4 and Dpo1 in the archaeal TLS process, thus achieving more efficient lesion bypass.

scholarly journals Mechanism of Translesion Synthesis Past an Equine Estrogen-DNA Adduct by Y-Family DNA Polymerases

2007 ◽  
Vol 371 (5) ◽  
pp. 1151-1162 ◽  
Author(s):  
Manabu Yasui ◽  
Naomi Suzuki ◽  
Xiaoping Liu ◽  
Yoshinori Okamoto ◽  
Sung Yeon Kim ◽  
...  
Keyword(s):  
Dna Polymerases ◽  
Translesion Synthesis ◽  
Dna Adduct ◽  
Y Family

scholarly journals DNA polymerases ν and θ are required for efficient immunoglobulin V gene diversification in chicken

2010 ◽  
Vol 189 (7) ◽  
pp. 1117-1127 ◽  
Author(s):  
Masaoki Kohzaki ◽  
Kana Nishihara ◽  
Kouji Hirota ◽  
Eiichiro Sonoda ◽  
Michio Yoshimura ◽  
...  
Keyword(s):  
Dna Synthesis ◽  
Gene Conversion ◽  
B Lymphocyte ◽  
Dna Polymerases ◽  
Point Mutations ◽  
Triple Mutant ◽  
Translesion Dna Synthesis ◽  
Gene Diversification ◽  
V Genes

The chicken DT40 B lymphocyte line diversifies its immunoglobulin (Ig) V genes through translesion DNA synthesis–dependent point mutations (Ig hypermutation) and homologous recombination (HR)–dependent Ig gene conversion. The error-prone biochemical characteristic of the A family DNA polymerases Polν and Polθ led us to explore the role of these polymerases in Ig gene diversification in DT40 cells. Disruption of both polymerases causes a significant decrease in Ig gene conversion events, although POLN−/−/POLQ−/− cells exhibit no prominent defect in HR-mediated DNA repair, as indicated by no increase in sensitivity to camptothecin. Polη has also been previously implicated in Ig gene conversion. We show that a POLH−/−/POLN−/−/POLQ−/− triple mutant displays no Ig gene conversion and reduced Ig hypermutation. Together, these data define a role for Polν and Polθ in recombination and suggest that the DNA synthesis associated with Ig gene conversion is accounted for by three specialized DNA polymerases.

scholarly journals Translesion synthesis across the (6-4) photoproduct and its Dewar valence isomer by the Y-family and engineered DNA polymerases

2008 ◽  
Vol 52 (1) ◽  
pp. 339-340 ◽  
Author(s):  
J. Yamamoto ◽  
D. Loakes ◽  
C. Masutani ◽  
S. Simmyo ◽  
K. Urabe ◽  
...  
Keyword(s):  
Dna Polymerases ◽  
Translesion Synthesis ◽  
Y Family

scholarly journals CRISPR-Associated Primase-Polymerases are implicated in prokaryotic CRISPR-Cas adaptation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Katerina Zabrady ◽  
Matej Zabrady ◽  
Peter Kolesar ◽  
Arthur W. H. Li ◽  
Aidan J. Doherty
Keyword(s):  
Dna Repair ◽  
Dna Synthesis ◽  
Genome Stability ◽  
Dna Polymerases ◽  
Acquired Immunity ◽  
Strand Displacement ◽  
Genetic Studies ◽  
Type Iiia ◽  
Maintain Genome Stability ◽  
Cas Proteins

AbstractCRISPR-Cas pathways provide prokaryotes with acquired “immunity” against foreign genetic elements, including phages and plasmids. Although many of the proteins associated with CRISPR-Cas mechanisms are characterized, some requisite enzymes remain elusive. Genetic studies have implicated host DNA polymerases in some CRISPR-Cas systems but CRISPR-specific replicases have not yet been discovered. We have identified and characterised a family of CRISPR-Associated Primase-Polymerases (CAPPs) in a range of prokaryotes that are operonically associated with Cas1 and Cas2. CAPPs belong to the Primase-Polymerase (Prim-Pol) superfamily of replicases that operate in various DNA repair and replication pathways that maintain genome stability. Here, we characterise the DNA synthesis activities of bacterial CAPP homologues from Type IIIA and IIIB CRISPR-Cas systems and establish that they possess a range of replicase activities including DNA priming, polymerisation and strand-displacement. We demonstrate that CAPPs operonically-associated partners, Cas1 and Cas2, form a complex that possesses spacer integration activity. We show that CAPPs physically associate with the Cas proteins to form bespoke CRISPR-Cas complexes. Finally, we propose how CAPPs activities, in conjunction with their partners, may function to undertake key roles in CRISPR-Cas adaptation.

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