1TAQ

STRUCTURE OF TAQ DNA POLYMERASE


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.40 Å
  • R-Value Free: 0.323 
  • R-Value Work: 0.202 
  • R-Value Observed: 0.202 

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This is version 1.4 of the entry. See complete history


Literature

Crystal structure of Thermus aquaticus DNA polymerase.

Kim, Y.Eom, S.H.Wang, J.Lee, D.S.Suh, S.W.Steitz, T.A.

(1995) Nature 376: 612-616

  • DOI: https://doi.org/10.1038/376612a0
  • Primary Citation of Related Structures:  
    1TAQ

  • PubMed Abstract: 

    The DNA polymerase from Thermus aquaticus (Taq polymerase), famous for its use in the polymerase chain reaction, is homologous to Escherichia coli DNA polymerase I (pol I) Like pol I, Taq polymerase has a domain at its amino terminus (residues 1-290) that has 5' nuclease activity and a domain at its carboxy terminus that catalyses the polymerase reaction. Unlike pol I, the intervening domain in Taq polymerase has lost the editing 3'-5' exonuclease activity. Although the structure of the Klenow fragment of pol I has been known for ten years, that of the intact pol I has proved more elusive. The structure of Taq polymerase determined here at 2.4 A resolution shows that the structures of the polymerase domains of the thermostable enzyme and of the Klenow fragment are nearly identical, whereas the catalytically critical carboxylate residues that bind two metal ions are missing from the remnants of the 3'-5' exonuclease active site of Taq polymerase. The first view of the 5' nuclease domain, responsible for excising the Okazaki RNA in lagging-strand DNA replication, shows a cluster of conserved divalent metal-ion-binding carboxylates at the bottom of a cleft. The location of this 5'-nuclease active site some 70 A from the polymerase active site in this crystal form highlights the unanswered question of how this domain works in concert with the polymerase domain to produce a duplex DNA product that contains only a nick.


  • Organizational Affiliation

    Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520-8114, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
TAQ DNA POLYMERASE832Thermus aquaticusMutation(s): 0 
Gene Names: TAQ
EC: 2.7.7.7
UniProt
Find proteins for P19821 (Thermus aquaticus)
Explore P19821 
Go to UniProtKB:  P19821
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP19821
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.40 Å
  • R-Value Free: 0.323 
  • R-Value Work: 0.202 
  • R-Value Observed: 0.202 
  • Space Group: P 31 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 107.421α = 90
b = 107.421β = 90
c = 170.245γ = 120
Software Package:
Software NamePurpose
X-PLORmodel building
X-PLORrefinement
DENZOdata reduction
SCALEPACKdata scaling
X-PLORphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1996-12-07
    Type: Initial release
  • Version 1.1: 2008-03-03
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Data collection, Database references, Derived calculations, Other, Structure summary
  • Version 1.4: 2024-02-14
    Changes: Data collection, Database references, Structure summary