4M4W

Mechanistic implications for the bacterial primosome assembly of the structure of a helicase-helicase loader complex


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 6.1 Å
  • R-Value Free: 0.392 
  • R-Value Work: 0.379 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Structure of a helicase-helicase loader complex reveals insights into the mechanism of bacterial primosome assembly.

Liu, B.Eliason, W.K.Steitz, T.A.

(2013) Nat Commun 4: 2495-2495

  • DOI: 10.1038/ncomms3495

  • PubMed Abstract: 
  • During the assembly of the bacterial loader-dependent primosome, helicase loader proteins bind to the hexameric helicase ring, deliver it onto the oriC DNA and then dissociate from the complex. Here, to provide a better understanding of this key proc ...

    During the assembly of the bacterial loader-dependent primosome, helicase loader proteins bind to the hexameric helicase ring, deliver it onto the oriC DNA and then dissociate from the complex. Here, to provide a better understanding of this key process, we report the crystal structure of the ~570-kDa prepriming complex between the Bacillus subtilis loader protein and the Bacillus stearothermophilus helicase, as well as the helicase-binding domain of primase with a molar ratio of 6:6:3 at 7.5 Å resolution. The overall architecture of the complex exhibits a three-layered ring conformation. Moreover, the structure combined with the proposed model suggests that the shift from the 'open-ring' to the 'open-spiral' and then the 'closed-spiral' state of the helicase ring due to the binding of single-stranded DNA may be the cause of the loader release.


    Organizational Affiliation

    1] Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520, USA [2] Howard Hughes Medical Institute, New Haven, Connecticut 06510, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Replicative helicase
A, B, C, D, E, F
454Geobacillus stearothermophilusMutation(s): 0 
Gene Names: dnaB
EC: 3.6.4.12
Find proteins for Q9X4C9 (Geobacillus stearothermophilus)
Go to UniProtKB:  Q9X4C9
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
DNA primase
G, H, I
143Geobacillus stearothermophilusMutation(s): 0 
Gene Names: dnaG
EC: 2.7.7.-
Find proteins for Q9X4D0 (Geobacillus stearothermophilus)
Go to UniProtKB:  Q9X4D0
Entity ID: 3
MoleculeChainsSequence LengthOrganismDetails
Primosomal protein DnaI
J, K, L, M, N, O
317Bacillus subtilis (strain 168)Mutation(s): 0 
Gene Names: dnaI (ytxA)
Find proteins for P06567 (Bacillus subtilis (strain 168))
Go to UniProtKB:  P06567
Small Molecules
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
MSE
Query on MSE
G, H, I
L-PEPTIDE LINKINGC5 H11 N O2 SeMET
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 6.1 Å
  • R-Value Free: 0.392 
  • R-Value Work: 0.379 
  • Space Group: P 31 2 1
Unit Cell:
Length (Å)Angle (°)
a = 229.055α = 90.00
b = 229.055β = 90.00
c = 364.294γ = 120.00
Software Package:
Software NamePurpose
CBASSdata collection
REFMACrefinement
HKL-2000data scaling
PHASERphasing
HKL-2000data reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2013-09-25
    Type: Initial release
  • Version 1.1: 2013-10-02
    Type: Database references