Function of a strand-separation pin element in the PriA DNA replication restart helicase

Windgassen, Tricia A.; Leroux, Maxime; Sandler, Steven J.; Keck, James L.

doi:10.1074/jbc.ra118.006870

Cited by 20 publications

(18 citation statements)

References 82 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…First, OB‐folds and SH3 domains are structurally almost identical, with the folds aligning very well with an average root mean square deviation of less than 2.0 Å for the β‐strands 29 . Second, SSB and many of its interactome partners each contain an OB‐fold 3,9,30–34 . Third, the SSB linker contains three, well‐conserved conserved PXXP motifs 21 .…”

Section: Introductionmentioning

confidence: 99%

The mechanism of Single strand binding protein–RecG binding: Implications for SSB interactome function

et al. 2020

View full text Add to dashboard Cite

The Escherichia coli single-strand DNA binding protein (SSB) is essential to viability where it functions to regulate SSB interactome function. Here it binds to single-stranded DNA and to target proteins that comprise the interactome. The region of SSB that links these two essential protein functions is the intrinsically disordered linker. Key to linker function is the presence of three, conserved PXXP motifs that mediate binding to oligosaccharide-oligonucleotide binding folds (OB-fold) present in SSB and its interactome partners. Not surprisingly, partner OB-fold deletions eliminate SSB binding. Furthermore, single point mutations in either the PXXP motifs or, in the RecG OB-fold, obliterate SSB binding. The data also demonstrate that, and in contrast to the view currently held in the field, the C-terminal acidic tip of SSB is not required for interactome partner binding. Instead, we propose the tip has two roles.First, and consistent with the proposal of Dixon, to regulate the structure of the C-terminal domain in a biologically active conformation that prevents linkers from binding to SSB OB-folds until this interaction is required. Second, as a secondary binding domain. Finally, as OB-folds are present in SSB and many of its partners, we present the SSB interactome as the first family of OB-fold genome guardians identified in prokaryotes. K E Y W O R D SDNA helicase, OB-fold, PXXP motif, RecG, SH3 domain, single-strand binding protein, SSB interactome

show abstract

Section: Introductionmentioning

confidence: 99%

The mechanism of Single strand binding protein–RecG binding: Implications for SSB interactome function

et al. 2020

View full text Add to dashboard Cite

show abstract

“…PriA has a two-domain architecture: an N-terminal DNA binding domain (DBD) and a C-terminal helicase domain (HD) (15)(16)(17)(18)(19)(20). The cooperation among each domain preserves the recognition and binding activity of PriA to various DNA constructs as well as the interaction with other proteins (6,21,22).…”

Section: Introductionmentioning

confidence: 99%

Atomic force microscopy–based characterization of the interaction of PriA helicase with stalled DNA replication forks

Wang

Sun

Bianco

et al. 2020

Journal of Biological Chemistry

View full text Add to dashboard Cite

In bacteria, the restart of stalled DNA replication forks requires the DNA helicase PriA. PriA can recognize and remodel abandoned DNA replication forks, unwind DNA in the 3′-to-5′ direction, and facilitate the loading of the helicase DnaB onto the DNA to restart replication. Single-stranded DNA–binding protein (SSB) is typically present at the abandoned forks, but it is unclear how SSB and PriA interact, although it has been shown that the two proteins interact both physically and functionally. Here, we used atomic force microscopy to visualize the interaction of PriA with DNA substrates with or without SSB. These experiments were done in the absence of ATP to delineate the substrate recognition pattern of PriA before its ATP-catalyzed DNA-unwinding reaction. These analyses revealed that in the absence of SSB, PriA binds preferentially to a fork substrate with a gap in the leading strand. Such a preference has not been observed for 5′- and 3′-tailed duplexes, suggesting that it is the fork structure that plays an essential role in PriA's selection of DNA substrates. Furthermore, we found that in the absence of SSB, PriA binds exclusively to the fork regions of the DNA substrates. In contrast, fork-bound SSB loads PriA onto the duplex DNA arms of forks, suggesting a remodeling of PriA by SSB. We also demonstrate that the remodeling of PriA requires a functional C-terminal domain of SSB. In summary, our atomic force microscopy analyses reveal key details in the interactions between PriA and stalled DNA replication forks with or without SSB.

show abstract

“…Critically, SH3 domains are structurally, virtually identical to OB-folds with the folds aligning very well with an average root mean square deviation of less than 2.0 Å for the β-strands [77]. Importantly, OB-folds are present in both SSB and as many as twelve interactome partners [44,67,[78][79][80][81][82]. Consequently, binding involves the docking of the linker of SSB into the OB-fold present in the partner protein (Figure 4 and [60,63]).…”

Section: Ssb-the Mediator Of Dna Transactions At Forksmentioning

confidence: 99%

DNA Helicase-SSB Interactions Critical to the Regression and Restart of Stalled DNA Replication Forks in Escherichia coli

Bianco

2020

Genes

View full text Add to dashboard Cite

In Escherichia coli, DNA replication forks stall on average once per cell cycle. When this occurs, replisome components disengage from the DNA, exposing an intact, or nearly intact fork. Consequently, the fork structure must be regressed away from the initial impediment so that repair can occur. Regression is catalyzed by the powerful, monomeric DNA helicase, RecG. During this reaction, the enzyme couples unwinding of fork arms to rewinding of duplex DNA resulting in the formation of a Holliday junction. RecG works against large opposing forces enabling it to clear the fork of bound proteins. Following subsequent processing of the extruded junction, the PriA helicase mediates reloading of the replicative helicase DnaB leading to the resumption of DNA replication. The single-strand binding protein (SSB) plays a key role in mediating PriA and RecG functions at forks. It binds to each enzyme via linker/OB-fold interactions and controls helicase-fork loading sites in a substrate-dependent manner that involves helicase remodeling. Finally, it is displaced by RecG during fork regression. The intimate and dynamic SSB-helicase interactions play key roles in ensuring fork regression and DNA replication restart.

show abstract

Function of a strand-separation pin element in the PriA DNA replication restart helicase

Cited by 20 publications

References 82 publications

The mechanism of Single strand binding protein–RecG binding: Implications for SSB interactome function

The mechanism of Single strand binding protein–RecG binding: Implications for SSB interactome function

Atomic force microscopy–based characterization of the interaction of PriA helicase with stalled DNA replication forks

DNA Helicase-SSB Interactions Critical to the Regression and Restart of Stalled DNA Replication Forks in Escherichia coli

Contact Info

Product

Resources

About