2A1K

RB69 single-stranded DNA binding protein core domain


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.259 
  • R-Value Work: 0.236 
  • R-Value Observed: 0.243 

Starting Model: experimental
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wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Structure and enzymatic properties of a chimeric bacteriophage RB69 DNA polymerase and single-stranded DNA binding protein with increased processivity.

Sun, S.Geng, L.Shamoo, Y.

(2006) Proteins 65: 231-238

  • DOI: https://doi.org/10.1002/prot.21088
  • Primary Citation of Related Structures:  
    2A1K, 2ATQ

  • PubMed Abstract: 

    In vivo, replicative DNA polymerases are made more processive by their interactions with accessory proteins at the replication fork. Single-stranded DNA binding protein (SSB) is an essential protein that binds tightly and cooperatively to single-stranded DNA during replication to remove adventitious secondary structures and protect the exposed DNA from endogenous nucleases. Using information from high resolution structures and biochemical data, we have engineered a functional chimeric enzyme of the bacteriophage RB69 DNA polymerase and SSB with substantially increased processivity. Fusion of RB69 DNA polymerase with its cognate SSB via a short six amino acid linker increases affinity for primer-template DNA by sixfold and subsequently increases processivity by sevenfold while maintaining fidelity. The crystal structure of this fusion protein was solved by a combination of multiwavelength anomalous diffraction and molecular replacement to 3.2 A resolution and shows that RB69 SSB is positioned proximal to the N-terminal domain of RB69 DNA polymerase near the template strand channel. The structural and biochemical data suggest that SSB interactions with DNA polymerase are transient and flexible, consistent with models of a dynamic replisome during elongation.


  • Organizational Affiliation

    Department of Biochemistry and Cell Biology, Rice University, Houston, Texas 77005, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
gp32 single stranded DNA binding protein
A, B
233Escherichia phage RB69Mutation(s): 0 
Gene Names: 32
UniProt
Find proteins for Q7Y265 (Escherichia phage RB69)
Explore Q7Y265 
Go to UniProtKB:  Q7Y265
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ7Y265
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.259 
  • R-Value Work: 0.236 
  • R-Value Observed: 0.243 
  • Space Group: P 43
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 67.7α = 90
b = 67.7β = 90
c = 123.75γ = 90
Software Package:
Software NamePurpose
d*TREKdata scaling
CNSrefinement
PDB_EXTRACTdata extraction
CrystalCleardata reduction
CNSphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2006-05-09
    Type: Initial release
  • Version 1.1: 2008-04-30
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2023-08-23
    Changes: Data collection, Database references, Derived calculations, Refinement description