1G8Y

CRYSTAL STRUCTURE OF THE HEXAMERIC REPLICATIVE HELICASE REPA OF PLASMID RSF1010


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.264 
  • R-Value Work: 0.221 

wwPDB Validation 3D Report Full Report


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

  • 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- ...

    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

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
REGULATORY PROTEIN REPA
A, B, C, D, E, F, G, H, I, J, K, L
279Escherichia coliGene Names: repA
Find proteins for P20356 (Escherichia coli)
Go to UniProtKB:  P20356
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 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 = 90.00
b = 179.156β = 108.80
c = 116.289γ = 90.00
Software Package:
Software NamePurpose
MLPHAREphasing
SCALEPACKdata scaling
CNSrefinement
DENZOdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

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