Biological Assembly 1  

 3D View: Structure | Electron Density

Global Symmetry: Cyclic - C3  (3D View)
Global Stoichiometry: Homo 3-mer - A3 

Biological assembly 1 assigned by authors and generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 165.03 kDa 
• Atom Count: 10421 
• Residue Count: 1275 
• Unique protein chains: 1

4C8H

Crystal structure of the C-terminal region of yeast Ctf4, selenomethionine protein.

• DOI: 10.2210/pdb4C8H/pdb

• Classification: DNA REPLICATION
• Organism(s): Saccharomyces cerevisiae
• Expression System: Escherichia coli BL21(DE3)
• Mutation(s): No 


• Deposited: 2013-10-01 Released: 2014-04-30 
• Deposition Author(s): Simon, A.C., Pellegrini, L.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.69 Å
• R-Value Free: 0.225 
• R-Value Work: 0.190 
• R-Value Observed: 0.191 

Literature

A Ctf4 Trimer Couples the Cmg Helicase to DNA Polymerase Alpha in the Eukaryotic Replisome

Simon, A.C., Zhou, J.C., Perera, R.L., Vandeursen, F., Evrin, C., Ivanova, M.E., Kilkenny, M.L., Renault, L., Kjaer, S., Matak-Vinkovic, D., Labib, K., Costa, A., Pellegrini, L.

(2014) Nature 510: 293

• PubMed: 24805245 
• DOI: 10.1038/nature13234
• Primary Citation of Related Structures:  
  4C8H, 4C93, 4C8S, 4C95


• PubMed Abstract: 
  

Efficient duplication of the genome requires the concerted action of helicase and DNA polymerases at replication forks to avoid stalling of the replication machinery and consequent genomic instability. In eukaryotes, the physical coupling between helicase and DNA polymerases remains poorly understood. Here we define the molecular mechanism by which the yeast Ctf4 protein links the Cdc45-MCM-GINS (CMG) DNA helicase to DNA polymerase α (Pol α) within the replisome. We use X-ray crystallography and electron microscopy to show that Ctf4 self-associates in a constitutive disk-shaped trimer. Trimerization depends on a β-propeller domain in the carboxy-terminal half of the protein, which is fused to a helical extension that protrudes from one face of the trimeric disk. Critically, Pol α and the CMG helicase share a common mechanism of interaction with Ctf4. We show that the amino-terminal tails of the catalytic subunit of Pol α and the Sld5 subunit of GINS contain a conserved Ctf4-binding motif that docks onto the exposed helical extension of a Ctf4 protomer within the trimer. Accordingly, we demonstrate that one Ctf4 trimer can support binding of up to three partner proteins, including the simultaneous association with both Pol α and GINS. Our findings indicate that Ctf4 can couple two molecules of Pol α to one CMG helicase within the replisome, providing a new model for lagging-strand synthesis in eukaryotes that resembles the emerging model for the simpler replisome of Escherichia coli. The ability of Ctf4 to act as a platform for multivalent interactions illustrates a mechanism for the concurrent recruitment of factors that act together at the fork.

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Organizational Affiliation: 

Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, UK.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
CTF4	A, B, C	478	Saccharomyces cerevisiae	Mutation(s): 0
Find proteins for Q01454 (Saccharomyces cerevisiae (strain ATCC 204508 / S288c)) Explore Q01454  Go to UniProtKB:  Q01454

Small Molecules

Modified Residues  1 Unique
ID	Chains	Type	Formula	2D Diagram	Parent
MSE	A,B,C	L-PEPTIDE LINKING	C5 H11 N O2 Se		MET

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.69 Å
• R-Value Free: 0.225 
• R-Value Work: 0.190 
• R-Value Observed: 0.191 
• Space Group: P 2 2₁ 2₁

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 107.294	α = 90
b = 118.428	β = 90
c = 155.697	γ = 90

Software Package:

Software Name	Purpose
PHENIX	refinement
XDS	data reduction
Aimless	data scaling
PHENIX	phasing

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2013-10-01 
• Released Date: 2014-04-30 
Deposition Author(s): Simon, A.C., Pellegrini, L.

Revision History 

• Version 1.0: 2014-04-30
  Type: Initial release
  
• Version 1.1: 2014-05-07
  Changes: Database references
• Version 1.2: 2014-05-21
  Changes: Database references
• Version 1.3: 2014-06-18
  Changes: Database references