1XXI

ADP Bound E. coli Clamp Loader Complex


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 4.10 Å
  • R-Value Free: 0.369 
  • R-Value Work: 0.366 

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This is version 1.2 of the entry. See complete history


Literature

Structural analysis of the inactive state of the Escherichia coli DNA polymerase clamp-loader complex

Kazmirski, S.L.Podobnik, M.Weitze, T.F.O'donnell, M.Kuriyan, J.

(2004) Proc Natl Acad Sci U S A 101: 16750-16755

  • DOI: 10.1073/pnas.0407904101
  • Primary Citation of Related Structures:  
    1XXH, 1XXI

  • PubMed Abstract: 
  • Clamp-loader complexes are heteropentameric AAA+ ATPases that load sliding clamps onto DNA. The structure of the nucleotide-free Escherichia coli clamp loader had been determined previously and led to the proposal that the clamp-loader cycles between an inactive state, in which the ATPase domains form a closed ring, and an active state that opens up to form a "C" shape ...

    Clamp-loader complexes are heteropentameric AAA+ ATPases that load sliding clamps onto DNA. The structure of the nucleotide-free Escherichia coli clamp loader had been determined previously and led to the proposal that the clamp-loader cycles between an inactive state, in which the ATPase domains form a closed ring, and an active state that opens up to form a "C" shape. The crystal structure was interpreted as being closer to the active state than the inactive state. The crystal structure of a nucleotide-bound eukaryotic clamp loader [replication factor C (RFC)] revealed a different and more tightly packed spiral organization of the ATPase domains, raising questions about the significance of the conformation seen earlier for the bacterial clamp loader. We describe crystal structures of the E. coli clamp-loader complex bound to the ATP analog ATPgammaS (at a resolution of 3.5 A) and ADP (at a resolution of 4.1 A). These structures are similar to that of the nucleotide-free clamp-loader complex. Only two of the three functional ATP-binding sites are occupied by ATPgammaS or ADP in these structures, and the bound nucleotides make no interfacial contacts in the complex. These results, along with data from isothermal titration calorimetry, molecular dynamics simulations, and comparison with the RFC structure, suggest that the more open form of the E. coli clamp loader described earlier and in the present work corresponds to a stable inactive state of the clamp loader in which the ATPase domains are prevented from engaging the clamp in the highly cooperative manner seen in the fully ATP-loaded RFC-clamp structure.


    Organizational Affiliation

    Department of Molecular and Cell Biology, Howard Hughes Medical Institute, University of California, Berkeley, CA 94720, USA.



Macromolecules
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Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
DNA polymerase III, delta subunitA, F343Escherichia coliMutation(s): 0 
Gene Names: holA
EC: 2.7.7.7
UniProt
Find proteins for P28630 (Escherichia coli (strain K12))
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Go to UniProtKB:  P28630
Entity Groups  
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UniProt GroupP28630
Protein Feature View
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  • Reference Sequence
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Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
DNA polymerase III subunit gamma
B, C, D, G, H, I
B, C, D, G, H, I
368Escherichia coliMutation(s): 0 
Gene Names: dnaXdnaZdnaZX
EC: 2.7.7.7
UniProt
Find proteins for P06710 (Escherichia coli (strain K12))
Explore P06710 
Go to UniProtKB:  P06710
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UniProt GroupP06710
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Entity ID: 3
MoleculeChainsSequence LengthOrganismDetailsImage
DNA polymerase III, delta prime subunitE, J334Escherichia coliMutation(s): 0 
Gene Names: holB
EC: 2.7.7.7
UniProt
Find proteins for P28631 (Escherichia coli (strain K12))
Explore P28631 
Go to UniProtKB:  P28631
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP28631
Protein Feature View
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  • Reference Sequence
Small Molecules
Binding Affinity Annotations 
IDSourceBinding Affinity
ADP PDBBind:  1XXI Kd: 3000 (nM) from 1 assay(s)
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 4.10 Å
  • R-Value Free: 0.369 
  • R-Value Work: 0.366 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 98.208α = 90
b = 106.574β = 90
c = 535.829γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALAdata scaling
AMoREphasing
CNSrefinement
CCP4data scaling

Structure Validation

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Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2004-12-07
    Type: Initial release
  • Version 1.1: 2008-04-30
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance