1E0K

gp4d helicase from phage T7


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.3 Å
  • R-Value Free: 0.308 
  • R-Value Work: 0.254 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Crystal Structure of T7 Gene 4 Ring Helicase Indicates a Mechanism for Sequential Hydrolysis of Nucleotides

Singleton, M.R.Sawaya, M.R.Ellenberger, T.Wigley, D.B.

(2000) Cell 101: 589

  • Primary Citation of Related Structures:  1E0J

  • PubMed Abstract: 
  • We have determined the crystal structure of an active, hexameric fragment of the gene 4 helicase from bacteriophage T7. The structure reveals how subunit contacts stabilize the hexamer. Deviation from expected six-fold symmetry of the hexamer indicat ...

    We have determined the crystal structure of an active, hexameric fragment of the gene 4 helicase from bacteriophage T7. The structure reveals how subunit contacts stabilize the hexamer. Deviation from expected six-fold symmetry of the hexamer indicates that the structure is of an intermediate on the catalytic pathway. The structural consequences of the asymmetry suggest a "binding change" mechanism to explain how cooperative binding and hydrolysis of nucleotides are coupled to conformational changes in the ring that most likely accompany duplex unwinding. The structure of a complex with a nonhydrolyzable ATP analog provides additional evidence for this hypothesis, with only four of the six possible nucleotide binding sites being occupied in this conformation of the hexamer. This model suggests a mechanism for DNA translocation.


    Organizational Affiliation

    Sir William Dunn School of Pathology, University of Oxford, United Kingdom.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
DNA HELICASE
A, B, C, D, E, F
289Enterobacteria phage T7EC: 3.6.4.12, 2.7.7.-
Find proteins for P03692 (Enterobacteria phage T7)
Go to UniProtKB:  P03692
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.3 Å
  • R-Value Free: 0.308 
  • R-Value Work: 0.254 
  • Space Group: P 41 21 2
Unit Cell:
Length (Å)Angle (°)
a = 120.650α = 90.00
b = 120.650β = 90.00
c = 284.500γ = 90.00
Software Package:
Software NamePurpose
SCALEPACKdata scaling
CNSrefinement
CNSphasing
DENZOdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2000-06-09
    Type: Initial release
  • Version 1.1: 2011-05-08
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance