PriA Helicase Bound to ADP

Experimental Data Snapshot

  • Resolution: 2.65 Å
  • R-Value Free: 0.254 
  • R-Value Work: 0.218 
  • R-Value Observed: 0.220 

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Structural mechanisms of PriA-mediated DNA replication restart.

Bhattacharyya, B.George, N.P.Thurmes, T.M.Zhou, R.Jani, N.Wessel, S.R.Sandler, S.J.Ha, T.Keck, J.L.

(2014) Proc Natl Acad Sci U S A 111: 1373-1378

  • DOI: https://doi.org/10.1073/pnas.1318001111
  • Primary Citation of Related Structures:  
    4NL4, 4NL8

  • PubMed Abstract: 

    Collisions between cellular DNA replication machinery (replisomes) and damaged DNA or immovable protein complexes can dissociate replisomes before the completion of replication. This potentially lethal problem is resolved by cellular "replication restart" reactions that recognize the structures of prematurely abandoned replication forks and mediate replisomal reloading. In bacteria, this essential activity is orchestrated by the PriA DNA helicase, which identifies replication forks via structure-specific DNA binding and interactions with fork-associated ssDNA-binding proteins (SSBs). However, the mechanisms by which PriA binds replication fork DNA and coordinates subsequent replication restart reactions have remained unclear due to the dearth of high-resolution structural information available for the protein. Here, we describe the crystal structures of full-length PriA and PriA bound to SSB. The structures reveal a modular arrangement for PriA in which several DNA-binding domains surround its helicase core in a manner that appears to be poised for binding to branched replication fork DNA structures while simultaneously allowing complex formation with SSB. PriA interaction with SSB is shown to modulate SSB/DNA complexes in a manner that exposes a potential replication initiation site. From these observations, a model emerges to explain how PriA links recognition of diverse replication forks to replication restart.

  • Organizational Affiliation

    Department of Biomolecular Chemistry, School of Medicine and Public Health, University of Wisconsin, Madison, WI 53706.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Primosome assembly protein PriAA [auth H]747Klebsiella pneumoniae subsp. pneumoniae MGH 78578Mutation(s): 0 
Gene Names: KPN78578_41850KPN_04230priA
EC: 3.6.4
Find proteins for A6TGC5 (Klebsiella pneumoniae subsp. pneumoniae (strain ATCC 700721 / MGH 78578))
Explore A6TGC5 
Go to UniProtKB:  A6TGC5
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupA6TGC5
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.65 Å
  • R-Value Free: 0.254 
  • R-Value Work: 0.218 
  • R-Value Observed: 0.220 
  • Space Group: P 32
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 85.433α = 90
b = 85.433β = 90
c = 111.682γ = 120
Software Package:
Software NamePurpose
ADSCdata collection
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

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Ligand Structure Quality Assessment 

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2014-01-08
    Type: Initial release
  • Version 1.1: 2014-02-12
    Changes: Database references
  • Version 1.2: 2015-05-27
    Changes: Refinement description