3SXU

Structure of the E. coli SSB-DNA polymerase III interface


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free: 0.208 
  • R-Value Work: 0.184 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Structure of the SSB-DNA polymerase III interface and its role in DNA replication.

Marceau, A.H.Bahng, S.Massoni, S.C.George, N.P.Sandler, S.J.Marians, K.J.Keck, J.L.

(2011) Embo J. 30: 4236-4247

  • DOI: 10.1038/emboj.2011.305

  • PubMed Abstract: 
  • Interactions between single-stranded DNA-binding proteins (SSBs) and the DNA replication machinery are found in all organisms, but the roles of these contacts remain poorly defined. In Escherichia coli, SSB's association with the χ subunit of the DNA ...

    Interactions between single-stranded DNA-binding proteins (SSBs) and the DNA replication machinery are found in all organisms, but the roles of these contacts remain poorly defined. In Escherichia coli, SSB's association with the χ subunit of the DNA polymerase III holoenzyme has been proposed to confer stability to the replisome and to aid delivery of primers to the lagging-strand DNA polymerase. Here, the SSB-binding site on χ is identified crystallographically and biochemical and cellular studies delineate the consequences of destabilizing the χ/SSB interface. An essential role for the χ/SSB interaction in lagging-strand primer utilization is not supported. However, sequence changes in χ that block complex formation with SSB lead to salt-dependent uncoupling of leading- and lagging-strand DNA synthesis and to a surprising obstruction of the leading-strand DNA polymerase in vitro, pointing to roles for the χ/SSB complex in replisome establishment and maintenance. Destabilization of the χ/SSB complex in vivo produces cells with temperature-dependent cell cycle defects that appear to arise from replisome instability.


    Organizational Affiliation

    Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706-1532, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
DNA polymerase III subunit chi
A
150Escherichia coli (strain K12)Mutation(s): 0 
Gene Names: holC
EC: 2.7.7.7
Find proteins for P28905 (Escherichia coli (strain K12))
Go to UniProtKB:  P28905
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
DNA polymerase III subunit psi
B
138Escherichia coli (strain K12)Mutation(s): 0 
Gene Names: holD
EC: 2.7.7.7
Find proteins for P28632 (Escherichia coli (strain K12))
Go to UniProtKB:  P28632
Entity ID: 3
MoleculeChainsSequence LengthOrganismDetails
SSB peptide
C
5Escherichia coli (strain K12)Mutation(s): 0 
Gene Names: ssb (exrB, lexC)
Find proteins for P0AGE0 (Escherichia coli (strain K12))
Go to UniProtKB:  P0AGE0
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free: 0.208 
  • R-Value Work: 0.184 
  • Space Group: P 61 2 2
Unit Cell:
Length (Å)Angle (°)
a = 79.927α = 90.00
b = 79.927β = 90.00
c = 155.045γ = 120.00
Software Package:
Software NamePurpose
HKL-2000data reduction
PHASERphasing
REFMACrefinement
ADSCdata collection
HKL-2000data scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2011-09-21
    Type: Initial release
  • Version 1.1: 2011-11-30
    Type: Database references