Evidence from mutational specificity studies that yeast DNA polymerases δ and ϵ replicate different DNA strands at an intracellular replication fork 1 1Edited by A. R. Fersht

2000 ◽  
Vol 299 (2) ◽  
pp. 405-419 ◽  
Author(s):  
Ramachandran Karthikeyan ◽  
Edward J Vonarx ◽  
Andrew F.L Straffon ◽  
Michel Simon ◽  
Gérard Faye ◽  
...  
Keyword(s):  
Replication Fork ◽  
Dna Polymerases ◽  
Intracellular Replication ◽  
Mutational Specificity ◽  
Dna Strands

scholarly journals DNA Polymerases at the Eukaryotic Replication Fork Thirty Years after: Connection to Cancer

Cancers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3489
Author(s):  
Youri I. Pavlov ◽  
Anna S. Zhuk ◽  
Elena I. Stepchenkova
Keyword(s):  
Replication Fork ◽  
Genome Instability ◽  
Dna Polymerases ◽  
Structure And Function ◽  
The Past ◽  
New Findings ◽  
Dna Strands ◽  
Leading Strand ◽  
And Function

Recent studies on tumor genomes revealed that mutations in genes of replicative DNA polymerases cause a predisposition for cancer by increasing genome instability. The past 10 years have uncovered exciting details about the structure and function of replicative DNA polymerases and the replication fork organization. The principal idea of participation of different polymerases in specific transactions at the fork proposed by Morrison and coauthors 30 years ago and later named “division of labor,” remains standing, with an amendment of the broader role of polymerase δ in the replication of both the lagging and leading DNA strands. However, cancer-associated mutations predominantly affect the catalytic subunit of polymerase ε that participates in leading strand DNA synthesis. We analyze how new findings in the DNA replication field help elucidate the polymerase variants’ effects on cancer.

scholarly journals 3′ → 5′ Exonucleases of DNA Polymerases ϵ and δ Correct Base Analog Induced DNA Replication Errors on Opposite DNA Strands in Saccharomyces cerevisiae

Genetics ◽  
1996 ◽  
Vol 142 (3) ◽  
pp. 717-726 ◽  
Author(s):  
Polina V Shcherbakova ◽  
Youri I Pavlov
Keyword(s):  
Dna Replication ◽  
Dna Polymerases ◽  
Replication Errors ◽  
Dna Strands ◽  
Base Analog ◽  
Chromosome Iii ◽  
Dna Strand ◽  
Dna Replication Errors ◽  
Yeast Mutants ◽  
Lagging Strand

Abstract The base analog 6-N-hydroxylaminopurine (HAP) induces bidirectional GC → AT and AT → GC transitions that are enhanced in DNA polymerase ϵ and δ 3′ → 5′ exonuclease-deficient yeast mutants, pol2-4 and pol3-01, respectively. We have constructed a set of isogenic strains to determine whether the DNA polymerases δ and ϵ contribute equally to proofreading of replication errors provoked by HAP during leading and lagging strand DNA synthesis. Site-specific GC → AT and AT → GC transitions in a Pol→, pol2-4 or pol3-01 genetic background were scored as reversions of ura3 missense alleles. At each site, reversion was increased in only one proofreading-deficient mutant, either pol2-4 or pol3-01, depending on the DNA strand in which HAP incorporation presumably occurred. Measurement of the HAP-induced reversion frequency of the ura3 alleles placed into chromosome III near to the defined active replication origin ARS306 in two orientations indicated that DNA polymerases ϵ and δ correct HAP-induced DNA replication errors on opposite DNA strands.

scholarly journals Single-molecule imaging of DNA gyrase activity in livingEscherichia coli

2018 ◽  
Author(s):  
Mathew Stracy ◽  
Adam J.M. Wollman ◽  
Elzbieta Kaja ◽  
Jacek Gapinski ◽  
Ji-Eun Lee ◽  
...  
Keyword(s):  
Single Molecule ◽  
High Speed ◽  
Replication Fork ◽  
Dna Gyrase ◽  
Chromosomal Dna ◽  
Replication Fork Progression ◽  
Dna Strands ◽  
Steady State Levels ◽  
Negative Supercoiling ◽  
Supercoil Relaxation

ABSTRACTBacterial DNA gyrase introduces negative supercoils into chromosomal DNA and relaxes positive supercoils introduced by replication and transiently by transcription. Removal of these positive supercoils is essential for replication fork progression and for the overall unlinking of the two duplex DNA strands, as well as for ongoing transcription. To address how gyrase copes with these topological challenges, we used high-speed single-molecule fluorescence imaging in liveEscherichia colicells. We demonstrate that at least 300 gyrase molecules are stably bound to the chromosome at any time, with ∼12 enzymes enriched near each replication fork. Trapping of reaction intermediates with ciprofloxacin revealed complexes undergoing catalysis. Dwell times of ∼2 s were observed for the dispersed gyrase molecules, which we propose maintain steady-state levels of negative supercoiling of the chromosome. In contrast, the dwell time of replisome-proximal molecules was ∼8 s, consistent with these catalyzing processive positive supercoil relaxation in front of the progressing replisome.

scholarly journals Impaired Translesion Synthesis in Xeroderma Pigmentosum Variant Extracts

1999 ◽  
Vol 19 (3) ◽  
pp. 2206-2211 ◽  
Author(s):  
Agnes M. Cordonnier ◽  
Alan R. Lehmann ◽  
Robert P. P. Fuchs
Keyword(s):  
Xeroderma Pigmentosum ◽  
Replication Fork ◽  
Molecular Mechanisms ◽  
Translesion Synthesis ◽  
Distinct Pattern ◽  
Skin Fibroblasts ◽  
Primer Extension ◽  
Normal Cells ◽  
Replication Fork Progression ◽  
Dna Strands

ABSTRACT Xeroderma pigmentosum variant (XPV) cells are characterized by a cellular defect in the ability to synthesize intact daughter DNA strands on damaged templates. Molecular mechanisms that facilitate replication fork progression on damaged DNA in normal cells are not well defined. In this study, we used single-stranded plasmid molecules containing a single N-2-acetylaminofluorene (AAF) adduct to analyze translesion synthesis (TLS) catalyzed by extracts of either normal or XPV primary skin fibroblasts. In one of the substrates, the single AAF adduct was located at the 3′ end of a run of three guanines that was previously shown to induce deletion of one G by a slippage mechanism. Primer extension reactions performed by normal cellular extracts from four different individuals produced the same distinct pattern of TLS, with over 80% of the products resulting from the elongation of a slipped intermediate and the remaining 20% resulting from a nonslipped intermediate. In contrast, with cellular extracts from five different XPV patients, the TLS reaction was strongly reduced, yielding only low amounts of TLS via the nonslipped intermediate. With our second substrate, in which the AAF adduct was located at the first G in the run, thus preventing slippage from occurring, we confirmed that normal extracts were able to perform TLS 10-fold more efficiently than XPV extracts. These data demonstrate unequivocally that the defect in XPV cells resides in translesion synthesis independently of the slippage process.

Mutational specificity of animal cell DNA polymerases

1986 ◽  
Vol 8 (5) ◽  
pp. 769-789 ◽  
Author(s):  
John D. Roberts ◽  
Thomas A. Kunkel
Keyword(s):  
Animal Cell ◽  
Dna Polymerases ◽  
Mutational Specificity

Uracil recognition by archaeal family B DNA polymerases

2003 ◽  
Vol 31 (3) ◽  
pp. 699-702 ◽  
Author(s):  
B.A. Connolly ◽  
M.J. Fogg ◽  
G. Shuttleworth ◽  
B.T. Wilson
Keyword(s):  
Dna Synthesis ◽  
Protein Interactions ◽  
Replication Fork ◽  
Dna Polymerases ◽  
Structural Basis ◽  
Dna Glycosylases ◽  
Protein Protein Interactions ◽  
Sensing Mechanism ◽  
Uridine Triphosphate

Archaeal family-B DNA polymerases possess a novel uracil-sensing mechanism. A specialized pocket scans the template, ahead of the replication fork, for the presence of uracil; on encountering this base, DNA synthesis is stalled. The structural basis for uracil recognition by polymerases is described and compared with other uracil-recognizing enzymes (uridine-triphosphate pyrophophatases and uracil-DNA glycosylases). Remarkably, protein–protein interactions between all three archaeal uracil sensors are observed; possibly the enzymes co-operate to efficiently eliminate uracil from archaeal genomes.

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