1G8Y

CRYSTAL STRUCTURE OF THE HEXAMERIC REPLICATIVE HELICASE REPA OF PLASMID RSF1010


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.40 Å
  • R-Value Free: 0.264 
  • R-Value Work: 0.221 

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This is version 1.2 of the entry. See complete history


Literature

Crystal structure of the hexameric replicative helicase RepA of plasmid RSF1010.

Niedenzu, T.Roleke, D.Bains, G.Scherzinger, E.Saenger, W.

(2001) J Mol Biol 306: 479-487

  • DOI: 10.1006/jmbi.2000.4398
  • Primary Citation of Related Structures:  
    1G8Y

  • PubMed Abstract: 
  • Unwinding of double-stranded DNA into single-stranded intermediates required for various fundamental life processes is catalyzed by helicases, a family of mono-, di- or hexameric motor proteins fueled by nucleoside triphosphate hydrolysis. The three-dimensional crystal structure of the hexameric helicase RepA encoded by plasmid RSF1010 has been determined by X-ray diffraction at 2 ...

    Unwinding of double-stranded DNA into single-stranded intermediates required for various fundamental life processes is catalyzed by helicases, a family of mono-, di- or hexameric motor proteins fueled by nucleoside triphosphate hydrolysis. The three-dimensional crystal structure of the hexameric helicase RepA encoded by plasmid RSF1010 has been determined by X-ray diffraction at 2.4 A resolution. The hexamer shows an annular structure with 6-fold rotational symmetry and a approximately 17 A wide central hole, suggesting that single-stranded DNA may be threaded during unwinding. Homologs of all five conserved sequence motifs of the DnaB-like helicase family are found in RepA, and the topography of the monomer resembles RecA and the helicase domain of the bacteriophage T7 gp4 protein. In a modeled complex, ATP molecules are located at the subunit interfaces and clearly define adenine-binding and ATPase catalytic sites formed by amino acid residues located on adjacent monomers; most remarkable is the "arginine finger" Arg207 contributing to the active site in the adjacent monomer. This arrangement of active-site residues suggests cooperativity between monomers in ATP hydrolysis and helicase activity of RepA. The mechanism of DNA unwinding remains elusive, as RepA is 6-fold symmetric, contrasting the recently published asymmetric structure of the bacteriophage T7 gp4 helicase domain.


    Organizational Affiliation

    Institut für Kristallographie, Freie Universität Berlin, Takustr. 6, Berlin, D-14195, Germany.



Macromolecules
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Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
REGULATORY PROTEIN REPA
A, B, C, D, E, F, G, H, I, J, K, L
A, B, C, D, E, F, G, H, I, J, K, L
279Escherichia coliMutation(s): 0 
Gene Names: REPA ON PLASMID INCQ RSF1010repA
UniProt
Find proteins for P20356 (Escherichia coli)
Explore P20356 
Go to UniProtKB:  P20356
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP20356
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.40 Å
  • R-Value Free: 0.264 
  • R-Value Work: 0.221 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 104.432α = 90
b = 179.156β = 108.8
c = 116.289γ = 90
Software Package:
Software NamePurpose
MLPHAREphasing
CNSrefinement
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2001-02-14
    Type: Initial release
  • Version 1.1: 2008-04-27
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance