scholarly journals Yeast Srs2 Helicase Promotes Redistribution of Single-Stranded DNA-Bound RPA and Rad52 in Homologous Recombination Regulation

Cell Reports ◽  
2017 ◽  
Vol 21 (3) ◽  
pp. 570-577 ◽  
Author(s):  
Luisina De Tullio ◽  
Kyle Kaniecki ◽  
Youngho Kwon ◽  
J. Brooks Crickard ◽  
Patrick Sung ◽  
...  
Keyword(s):  
Homologous Recombination ◽  
Single Stranded Dna ◽  
Srs2 Helicase

Multifaceted role of the Saccharomyces cerevisiae Srs2 helicase in homologous recombination regulation

2005 ◽  
Vol 33 (6) ◽  
pp. 1447-1450 ◽  
Author(s):  
M.A. Macris ◽  
P. Sung
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Death ◽  
Dna Replication ◽  
Homologous Recombination ◽  
High Energy ◽  
Yeast Saccharomyces Cerevisiae ◽  
Major Pathway ◽  
Dna Dsbs ◽  
Srs2 Helicase

Homologous recombination (HR) is a major pathway for the elimination of DNA DSBs (double-strand breaks) induced by high-energy radiation and chemicals, or that arise due to endogenous damage and stalled DNA replication forks. If not processed properly, DSBs can lead to cell death, chromosome aberrations and tumorigenesis. Even though HR is important for genome maintenance, it can also interfere with other DNA repair mechanisms and cause gross chromosome rearrangements. In addition, HR can generate DNA or nucleoprotein intermediates that elicit prolonged cell-cycle arrest and sometimes cell death. Genetic analyses in the yeast Saccharomyces cerevisiae have revealed a central role of the Srs2 helicase in preventing untimely HR events and in inhibiting the formation of potentially deleterious DNA structures or nucleoprotein complexes upon DNA replication stress. Paradoxically, efficient repair of DNA DSBs by HR is dependent on Srs2. In this paper, we review recent molecular studies aimed at deciphering the multifaceted role of Srs2 in HR and other cellular processes. These studies have provided critical insights into how HR is regulated in order to preserve genomic integrity and promote cell survival.

scholarly journals Homologous recombination between single-stranded DNA and chromosomal genes in Saccharomyces cerevisiae.

1987 ◽  
Vol 7 (7) ◽  
pp. 2329-2334 ◽  
Author(s):  
J R Simon ◽  
P D Moore
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Homologous Recombination ◽  
Gene Conversion ◽  
Mutant Gene ◽  
Transformation Process ◽  
Single Stranded Dna ◽  
Autonomous Replication ◽  
Double Stranded Dna ◽  
Chromosomal Genes ◽  
Chromosomal Sequences

Transformation of Saccharomyces cerevisiae strains was examined by using the URA3 and TRP1 genes cloned into M13 vectors in the absence of sequences capable of promoting autonomous replication. These constructs transform S. cerevisiae cells to prototrophy by homologous recombination with the resident mutant gene. Single-stranded DNA was found to transform S. cerevisiae cells at efficiencies greater than that of double-stranded DNA. No conversion of single-stranded transforming DNA into duplex forms could be detected during the transformation process, and we conclude that single-stranded DNA may participate directly in recombination with chromosomal sequences. Transformation with single-stranded DNA gave rise to both gene conversion and reciprocal exchange events. Cotransformation with competing heterologous single-stranded DNA specifically inhibited transformation by single-stranded DNA, suggesting that one of the components in the transformation-recombination process has a preferential affinity for single-stranded DNA.

Homologous recombination between single-stranded DNA and chromosomal genes in Saccharomyces cerevisiae

1987 ◽  
Vol 7 (7) ◽  
pp. 2329-2334
Author(s):  
J R Simon ◽  
P D Moore
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Homologous Recombination ◽  
Gene Conversion ◽  
Mutant Gene ◽  
Transformation Process ◽  
Single Stranded Dna ◽  
Autonomous Replication ◽  
Double Stranded Dna ◽  
Chromosomal Genes ◽  
Chromosomal Sequences

Transformation of Saccharomyces cerevisiae strains was examined by using the URA3 and TRP1 genes cloned into M13 vectors in the absence of sequences capable of promoting autonomous replication. These constructs transform S. cerevisiae cells to prototrophy by homologous recombination with the resident mutant gene. Single-stranded DNA was found to transform S. cerevisiae cells at efficiencies greater than that of double-stranded DNA. No conversion of single-stranded transforming DNA into duplex forms could be detected during the transformation process, and we conclude that single-stranded DNA may participate directly in recombination with chromosomal sequences. Transformation with single-stranded DNA gave rise to both gene conversion and reciprocal exchange events. Cotransformation with competing heterologous single-stranded DNA specifically inhibited transformation by single-stranded DNA, suggesting that one of the components in the transformation-recombination process has a preferential affinity for single-stranded DNA.

scholarly journals The Herpes Simplex Virus Type 1 Alkaline Nuclease and Single-Stranded DNA Binding Protein Mediate Strand Exchange In Vitro

2003 ◽  
Vol 77 (13) ◽  
pp. 7425-7433 ◽  
Author(s):  
Nina Bacher Reuven ◽  
Amy E. Staire ◽  
Richard S. Myers ◽  
Sandra K. Weller
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Homologous Recombination ◽  
Dna Binding Protein ◽  
Strand Exchange ◽  
Single Stranded Dna ◽  
Simplex Virus ◽  
Alkaline Nuclease ◽  
Hsv 1

ABSTRACT The replication of herpes simplex virus type 1 (HSV-1) DNA is associated with a high degree of homologous recombination. While cellular enzymes may take part in mediating this recombination, we present evidence for an HSV-1-encoded recombinase activity. HSV-1 alkaline nuclease, encoded by the UL12 gene, is a 5′→3′ exonuclease that shares homology with Redα, commonly known as λ exonuclease, an exonuclease required for homologous recombination by bacteriophage lambda. The HSV-1 single-stranded DNA binding protein ICP8 is an essential protein for HSV DNA replication and possesses single-stranded DNA annealing activities like the Redβ synaptase component of the phage lambda recombinase. Here we show that UL12 and ICP8 work together to effect strand exchange much like the Red system of lambda. Purified UL12 protein and ICP8 mediated the complete exchange between a 7.25-kb M13mp18 linear double-stranded DNA molecule and circular single-stranded M13 DNA, forming a gapped circle and a displaced strand as final products. The optimal conditions for strand exchange were 1 mM MgCl2, 40 mM NaCl, and pH 7.5. Stoichiometric amounts of ICP8 were required, and strand exchange did not depend on the nature of the double-stranded end. Nuclease-defective UL12 could not support this reaction. These data suggest that diverse DNA viruses appear to utilize an evolutionarily conserved recombination mechanism.

scholarly journals Mismatch sensing by nucleofilament deciphers mechanism of RecA-mediated homologous recombination

2020 ◽  
Vol 117 (34) ◽  
pp. 20549-20554
Author(s):  
Xingyuan Huang ◽  
Ying Lu ◽  
Shuang Wang ◽  
Mingyu Sui ◽  
Jinghua Li ◽  
...  
Keyword(s):  
Homologous Recombination ◽  
Single Molecule ◽  
Traveling Wave ◽  
Strand Exchange ◽  
Basic Unit ◽  
Base Pairs ◽  
Single Stranded Dna ◽  
Homologous Sequences ◽  
Transient Intermediates

Recombinases polymerize along single-stranded DNA (ssDNA) at the end of a broken DNA to form a helical nucleofilament with a periodicity of ∼18 bases. The filament catalyzes the search and checking for homologous sequences and promotes strand exchange with a donor duplex during homologous recombination (HR), the mechanism of which has remained mysterious since its discovery. Here, by inserting mismatched segments into donor duplexes and using single-molecule techniques to catch transient intermediates in HR, we found that, even though 3 base pairs (bp) is still the basic unit, both the homology checking and the strand exchange may proceed in multiple steps at a time, resulting in ∼9-bp large steps on average. More interestingly, the strand exchange is blocked remotely by the mismatched segment, terminating at positions ∼9 bp before the match–mismatch joint. The homology checking and the strand exchange are thus separated in space, with the strand exchange lagging behind. Our data suggest that the strand exchange progresses like a traveling wave in which the donor DNA is incorporated successively into the ssDNA–RecA filament to check homology in ∼9-bp steps in the frontier, followed by a hypothetical transitional segment and then the post-strand-exchanged duplex.

scholarly journals Single-Stranded DNA-Binding Protein and Exogenous RecBCD Inhibitors Enhance Phage-Derived Homologous Recombination in Pseudomonas

iScience ◽  
2019 ◽  
Vol 14 ◽  
pp. 1-14 ◽  
Author(s):  
Jia Yin ◽  
Wentao Zheng ◽  
Yunsheng Gao ◽  
Chanjuan Jiang ◽  
Hongbo Shi ◽  
...  
Keyword(s):  
Dna Binding ◽  
Homologous Recombination ◽  
Binding Protein ◽  
Dna Binding Protein ◽  
Single Stranded Dna
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