1NUI

Crystal Structure of the primase fragment of Bacteriophage T7 primase-helicase protein


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.90 Å
  • R-Value Free: 0.277 
  • R-Value Work: 0.235 
  • R-Value Observed: 0.237 

wwPDB Validation   3D Report Full Report


This is version 1.4 of the entry. See complete history


Literature

Modular Architecture of the Bacteriophage T7 Primase Couples RNA primer Synthesis to DNA Synthesis

Kato, M.Ito, T.Wagner, G.Richardson, C.C.Ellenberger, T.

(2003) Mol Cell 11: 1349-1360

  • DOI: https://doi.org/10.1016/s1097-2765(03)00195-3
  • Primary Citation of Related Structures:  
    1NUI

  • PubMed Abstract: 

    DNA primases are template-dependent RNA polymerases that synthesize oligoribonucleotide primers that can be extended by DNA polymerase. The bacterial primases consist of zinc binding and RNA polymerase domains that polymerize ribonucleotides at templating sequences of single-stranded DNA. We report a crystal structure of bacteriophage T7 primase that reveals its two domains and the presence of two Mg(2+) ions bound to the active site. NMR and biochemical data show that the two domains remain separated until the primase binds to DNA and nucleotide. The zinc binding domain alone can stimulate primer extension by T7 DNA polymerase. These findings suggest that the zinc binding domain couples primer synthesis with primer utilization by securing the DNA template in the primase active site and then delivering the primed DNA template to DNA polymerase. The modular architecture of the primase and a similar mechanism of priming DNA synthesis are likely to apply broadly to prokaryotic primases.


  • Organizational Affiliation

    Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA.


Macromolecules
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Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
DNA primase/helicase
A, B
255Escherichia phage T7Mutation(s): 1 
Gene Names: 4
EC: 2.7.7
UniProt
Find proteins for P03692 (Escherichia phage T7)
Explore P03692 
Go to UniProtKB:  P03692
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP03692
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.90 Å
  • R-Value Free: 0.277 
  • R-Value Work: 0.235 
  • R-Value Observed: 0.237 
  • Space Group: P 31 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 136.459α = 90
b = 136.46β = 90
c = 85.445γ = 120
Software Package:
Software NamePurpose
REFMACrefinement
DENZOdata reduction
SCALEPACKdata scaling
MLPHAREphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2003-05-27
    Type: Initial release
  • Version 1.1: 2008-04-29
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Advisory, Version format compliance
  • Version 1.3: 2021-10-27
    Changes: Database references, Derived calculations
  • Version 1.4: 2024-02-14
    Changes: Data collection, Refinement description