Biological Assembly 1  

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Global Symmetry: Helical - H  (3D View)
Global Stoichiometry: Homo 6-mer - A6 

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 33024.10 
• Atom Count: 1833 
• Residue Count: 296 
• Unique protein chains: 1

1CR0

CRYSTAL STRUCTURE OF THE HELICASE DOMAIN OF THE GENE4 PROTEIN OF BACTERIOPHAGE T7

• DOI: 10.2210/pdb1CR0/pdb

• Classification: TRANSFERASE
• Organism(s): Enterobacteria phage T7
• Expression System: Escherichia coli
• Mutation(s): 1 


• Deposited: 1999-08-12 Released: 1999-11-10 
• Deposition Author(s): Sawaya, M.R., Guo, S., Tabor, S., Richardson, C.C., Ellenberger, T.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.3 Å
• R-Value Free: 0.298 
• R-Value Work: 0.247 

Literature

Crystal structure of the helicase domain from the replicative helicase-primase of bacteriophage T7.

Sawaya, M.R., Guo, S., Tabor, S., Richardson, C.C., Ellenberger, T.

(1999) Cell 99: 167-177

• PubMed: 10535735 
• Primary Citation of Related Structures:  
  1CR4, 1CR2, 1CR1


• PubMed Abstract: 
  

Helicases that unwind DNA at the replication fork are ring-shaped oligomeric enzymes that move along one strand of a DNA duplex and catalyze the displacement of the complementary strand in a reaction that is coupled to nucleotide hydrolysis. The helicase domain of the replicative helicase-primase protein from bacteriophage T7 crystallized as a helical filament that resembles the Escherichia coli RecA protein, an ATP-dependent DNA strand exchange factor. When viewed in projection along the helical axis of the crystals, six protomers of the T7 helicase domain resemble the hexameric rings seen in electron microscopic images of the intact T7 helicase-primase. Nucleotides bind at the interface between pairs of adjacent subunits where an arginine is near the gamma-phosphate of the nucleotide in trans. The bound nucleotide stabilizes the folded conformation of a DNA-binding motif located near the center of the ring. These and other observations suggest how conformational changes are coupled to DNA unwinding activity.

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Organizational Affiliation: 

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

Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details
DNA PRIMASE/HELICASE	A	296	Enterobacteria phage T7	Mutation(s): 1  EC: 2.7.7.-, 3.6.4.12
Find proteins for P03692 (Enterobacteria phage T7) Go to UniProtKB:  P03692

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram & Interactions
SO4	A	SULFATE ION O4 S QAOWNCQODCNURD-UHFFFAOYSA-L

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.3 Å
• R-Value Free: 0.298 
• R-Value Work: 0.247 
• Space Group: P 6₁

Unit Cell:

Length (Å)	Angle (°)
a = 80.600	α = 90.00
b = 80.600	β = 90.00
c = 85.610	γ = 120.00

Software Package:

Software Name	Purpose
X-PLOR	refinement
MLPHARE	phasing
DENZO	data reduction
SCALEPACK	data scaling

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 1999-08-12 
• Released Date: 1999-11-10 
• Deposition Author(s): Sawaya, M.R., Guo, S., Tabor, S., Richardson, C.C., Ellenberger, T.

Revision History 

• Version 1.0: 1999-11-10
  Type: Initial release
• Version 1.1: 2008-04-27
  Type: Version format compliance
• Version 1.2: 2011-07-13
  Type: Version format compliance