Biological Assembly 1  

 3D View: Structure | Electron Density

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Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A 

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 91373.78 
• Atom Count: 6219 
• Residue Count: 742 
• Unique protein chains: 1
• Unique nucleic acid chains: 2

2P6R

Crystal structure of superfamily 2 helicase Hel308 in complex with unwound DNA

• DOI: 10.2210/pdb2P6R/pdb
• NDB: PD0984

• Classification: DNA binding protein/DNA
• Expression System: Escherichia coli


• Deposited: 2007-03-19 Released: 2007-06-12 
• Deposition Author(s): Buettner, K., Nehring, S., Hopfner, K.P.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 3 Å
• R-Value Free: 0.275 
• R-Value Work: 0.232 

Literature

Structural basis for DNA duplex separation by a superfamily-2 helicase.

Buttner, K., Nehring, S., Hopfner, K.P.

(2007) Nat.Struct.Mol.Biol. 14: 647-652

• PubMed: 17558417 
• DOI: 10.1038/nsmb1246
• Primary Citation of Related Structures:  
  2P6U


• PubMed Abstract: 
  

To reveal the mechanism of processive strand separation by superfamily-2 (SF2) 3'-->5' helicases, we determined apo and DNA-bound crystal structures of archaeal Hel308, a helicase that unwinds lagging strands and is related to human DNA polymerase theta. Our structure captures the duplex-unwinding reaction, shows that initial strand separation does not require ATP and identifies a prominent beta-hairpin loop as the unwinding element. Similar loops in hepatitis C virus NS3 helicase and RNA-decay factors support the idea that this duplex-unwinding mechanism is applicable to a broad subset of SF2 helicases. Comparison with ATP-bound SF2 enzymes suggests that ATP promotes processive unwinding of 1 base pair by ratchet-like transport of the 3' product strand. Our results provide a first structural framework for strand separation by processive SF2 3'-->5' helicases and reveal important mechanistic differences from SF1 helicases.

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Organizational Affiliation: 

Center for Integrated Protein Science, Gene Center and Department of Chemistry and Biochemistry, Ludwig-Maximilians-University Munich, Feodor-Lynen-Str. 25, 81377 Munich, Germany.

Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 3
Molecule	Chains	Sequence Length	Organism	Details
afUHEL308 HELICASE	A	702	N/A	Mutation(s): 0
Protein Feature View is not available: No corresponding UniProt sequence found.

Entity ID: 1
Molecule	Chains	Length	Organism
25-MER	X	25	N/A

Entity ID: 2
Molecule	Chains	Length	Organism
5'-D(*CP*TP*AP*GP*AP*GP*AP*CP*TP*AP*TP*CP*GP*AP*T)-3'	Y	15	N/A

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 3 Å
• R-Value Free: 0.275 
• R-Value Work: 0.232 
• Space Group: P 6₁ 2 2

Unit Cell:

Length (Å)	Angle (°)
a = 138.379	α = 90.00
b = 138.379	β = 90.00
c = 252.973	γ = 120.00

Software Package:

Software Name	Purpose
CNS	refinement
XDS	data scaling
PHASER	phasing
XDS	data reduction
PDB_EXTRACT	data extraction
XSCALE	data scaling

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2007-03-19 
• Released Date: 2007-06-12 
• Deposition Author(s): Buettner, K., Nehring, S., Hopfner, K.P.

Revision History 

• Version 1.0: 2007-06-12
  Type: Initial release
• Version 1.1: 2008-05-01
  Type: Version format compliance
• Version 1.2: 2011-07-13
  Type: Version format compliance