Situational Repair of Replication Forks

Robu, Mara E.; Inman, Ross B.; Cox, Michael M.

doi:10.1074/jbc.m312184200

Cited by 57 publications

(48 citation statements)

References 64 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…RecG interactions with HJ and replication fork substrates are not very stable in the presence of Mg 2ϩ , and the enzyme is not processive (12,40). Our results indicate that the peptides and RecG cannot both bind to a junction substrate, supporting our proposal that the peptides and the RecG wedge domain interact with junctions in a similar way.…”

Section: Discussionsupporting

confidence: 78%

Holliday junction-binding peptides inhibit distinct junction-processing enzymes

Kepple

Boldt

Segall

2005

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Holliday junctions (HJ) are the central intermediates in both homologous recombination and site-specific recombination performed by tyrosine recombinases such as the bacteriophage Integrase (Int) protein. Previously, our lab identified peptide inhibitors of Int-mediated recombination that prevent the resolution of HJ intermediates. We now show that two of these inhibitors bind HJ DNA in the square-planar conformation even in the absence of Int protein. The peptides prevent unwinding of branched DNA substrates by the RecG helicase of Escherichia coli and interfere with the resolution of HJ substrates by the RuvABC complex. Our results suggest that these peptides target all proteins that process HJ in the square-planar conformation. These inhibitors should be extremely useful for dissecting homologous recombination and recombination-dependent repair in vitro and in vivo.homologous recombination ͉ recombination-dependent repair ͉ RecG helicase ͉ RuvABC resolvasome ͉ tyrosine recombinase H olliday junctions (HJ), or four-way junctions, are central intermediates in homologous recombination, repair of collapsed replication forks, and reactions performed by the tyrosine recombinase family of site-specific enzymes (1-5). The first two processes are important in all organisms and are involved in the maintenance of chromosome integrity and repair of DNA damage. In the case of diploid organisms, faithful chromosome segregation depends on homologous recombination (6). Sitespecific recombination reactions performed by tyrosine recombinases are also very widespread and control gene expression, regulate plasmid and bacterial chromosome copy number, and mediate lysogeny (3). The presence and disappearance of HJ, their level within cells, and the enzymes that both generate and resolve them are of intense interest. More tools would be extremely useful for both in vitro and in vivo dissection of homologous recombination and repair processes in all organisms.Phage integrase (Int) binds to and mediates strand exchange between pairs of att sites. During recombination, one round of DNA cleavage, strand exchange, and ligation of the top strands of each partner DNA molecule generates a HJ intermediate, which is resolved by a second round of the same catalytic steps (3). These reactions are both rapid and highly reversible, making intermediates very difficult to study.We have identified peptides that inhibit recombination by trapping the protein-bound HJ intermediate and preventing its resolution either to substrates or to products (7-9). The most potent inhibitory peptide, WRWYCR, traps virtually all HJ formed during a reaction and has an IC 50 of 5-20 nM (9). A related peptide, KWWCRW, is very similar to WRWYCR in potency (8). These peptides also inhibit the mechanistically related Cre, XerC and D, and Flp proteins (ref. 9; A.M.S., unpublished results; A. Conway and P. A. Rice, personal communication). Because these proteins share little primary sequence identity, we reasoned that these peptides might interact with free HJ.HJ adopt one...

show abstract

Section: Discussionsupporting

confidence: 78%

Holliday junction-binding peptides inhibit distinct junction-processing enzymes

Kepple

Boldt

Segall

2005

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…propose that RecG would be devoted to fork regression and also fork rewinding, as observed for RecG Eco (22,58,59), whereas RuvAB should be mainly involved in HJ translocation. This is consistent with the observation that RuvAB Eco branch migration of the HJ is faster than its migration by RecA Eco -mediated strand exchange (60).…”

Section: Discussionmentioning

confidence: 99%

Interaction of Branch Migration Translocases with the Holliday Junction-resolving Enzyme and Their Implications in Holliday Junction Resolution

Cañas

Suzuki

Marchisone

et al. 2014

Journal of Biological Chemistry

View full text Add to dashboard Cite

Background: Bacillus subtilis RuvAB and RecG translocases and RecU resolvase are crucial in homologous recombination. Results: RecU interacts with RuvB and re-localizes it at a Holliday junction (HJ). RuvB stimulates RecU. RecG and RuvAB unwind HJs. Conclusion: A RecU⅐HJ⅐RuvAB complex might be formed. Significance: RecU, which interacts with RecA, may help to discriminate between RuvAB and RecG at HJs.

show abstract

“…Fork recovery pathways that involve fork reversal, where the original parental duplex is restored and nascent DNA strands pair, all require some critical amount of helicase unwinding (37,41). This is most likely necessary to allow sufficient DNA template for RecA (or RecG) binding to catalyze fork reversal (42) or sufficient buildup of superhelical tension to reverse the fork (43). Finally, fork processing pathways that involve degradation of nascent lagging strand DNA as a method to restore the parental duplex at the lesion site, followed by excision of the blocking lesion, also presumably require some critical amount of helicase unwinding (15).…”

Section: Discussionmentioning

confidence: 99%

Replisome Fate upon Encountering a Leading Strand Block and Clearance from DNA by Recombination Proteins

McInerney¹,

O'Donnell

2007

Journal of Biological Chemistry

View full text Add to dashboard Cite

Replication forks that collapse upon encountering a leading strand lesion are reactivated by a recombinative repair process called replication restart. Using rolling circle DNA substrates to model replication forks, we examine the fate of the helicase and both DNA polymerases when the leading strand polymerase is blocked. We find that the helicase continues over 0.5 kb but less than 3 kb and that the lagging strand DNA polymerase remains active despite its connection to a stalled leading strand enzyme. Furthermore, the blocked leading strand polymerase remains stably bound to the replication fork, implying that it must be dismantled from DNA in order for replication restart to initiate. Genetic studies have identified at least four gene products required for replication restart, RecF, RecO, RecR, and RecA. We find here that these proteins displace a stalled polymerase at a DNA template lesion. Implications of these results for replication fork collapse and recovery are discussed.

show abstract

Situational Repair of Replication Forks

Cited by 57 publications

References 64 publications

Holliday junction-binding peptides inhibit distinct junction-processing enzymes

Holliday junction-binding peptides inhibit distinct junction-processing enzymes

Interaction of Branch Migration Translocases with the Holliday Junction-resolving Enzyme and Their Implications in Holliday Junction Resolution

Replisome Fate upon Encountering a Leading Strand Block and Clearance from DNA by Recombination Proteins

Contact Info

Product

Resources

About