TITLE

The DnaB·DnaC complex: a structure based on dimers assembled around an occluded channel

AUTHOR(S)
Bárcena, Montserrat; Ruiz, Teresa; Donate, Luis Enrique; Brown, Susan E.; Dixon, Nicholas E.; Radermacher, Michael; Carazo, José María
PUB. DATE
March 2001
SOURCE
EMBO Journal;3/15/2001, Vol. 20 Issue 6, p1462
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
Replicative helicases are motor proteins that unwind DNA at replication forks. Escherichia coli DnaB is the best characterized member of this family of enzymes. We present the 26 Ã… resolution three-dimensional structure of the DnaB hexamer in complex with its loading partner, DnaC, obtained from cryo-electron microscopy. Analysis of the volume brings insight into the elaborate way the two proteins interact, and provides a structural basis for control of the symmetry state and inactivation of the helicase by DnaC. The complex is arranged on the basis of interactions among DnaC and DnaB dimers. DnaC monomers are observed for the first time to arrange as three dumb-bell-shaped dimers that interlock into one of the faces of the helicase. This could be responsible for the freezing of DnaB in a C3 architecture by its loading partner. The central channel of the helicase is almost occluded near the end opposite to DnaC, such that even single-stranded DNA could not pass through. We propose that the DnaB N-terminal domain is located at this face.
ACCESSION #
12954961

 

Related Articles

  • Replication fork reactivation downstream of a blocked nascent leading strand. Heller, Ryan C.; Marians, Kenneth J. // Nature;2/2/2006, Vol. 439 Issue 7076, p557 

    Unrepaired lesions in the DNA template pose a threat to accurate replication. Several pathways exist in Escherichia coli to reactivate a blocked replication fork. The process of recombination-dependent restart of broken forks is well understood, but the consequence of replication through...

  • Bacteriophage T4 UvsW protein is a helicase involved in recombination, repair and the regulation of DNA replication origins. Carles-Kinch, Kelly; George, James W.; Kreuzer, Kenneth N. // EMBO Journal;7/1/97, Vol. 16 Issue 13, p4142 

    Bacteriophage T4 UvsW protein is involved in phage recombination, repair and the regulation of replication origins. Here, we provide evidence that UvsW functions as a helicase. First, expression of UvsW allows growth of an (otherwise inviable) Escherichia coli recG rnhA double mutant, consistent...

  • Anticipating chromosomal replication fork arrest: SSB targets repair DNA helicases to active forks. Lecointe, François; Sérèna, Céline; Velten, Marion; Costes, Audrey; McGovern, Stephen; Meile, Jean-Christophe; Errington, Jeffrey; Ehrlich, S. Dusko; Noirot, Philippe; Polard, Patrice // EMBO Journal;10/10/2007, Vol. 26 Issue 19, p4239 

    In bacteria, several salvage responses to DNA replication arrest culminate in reassembly of the replisome on inactivated forks to resume replication. The PriA DNA helicase is a prominent trigger of this replication restart process, preceded in many cases by a repair and/or remodeling of the...

  • Biophysics: Helicase snaps back. Jankowsky, Eckhard // Nature;10/27/2005, Vol. 437 Issue 7063, p1245 

    Presents a study on the importance of proteins of the helicase family for almost all biological processes involving nucleic acids. Involvement of Escherichia coli in the replication of the bacterial genome; Analysis of the movement of individual monomers along single-stranded DNA; Function of...

  • Structure of the MutL C-terminal domain: a model of intact MutL and its roles in mismatch repair. Guarné, Alba; Ramon-Maiques, Santiago; Wolff, Erika M.; Ghirlando, Rodolfo; Xiaojian Hu; Miller, Jeffrey H.; Wei Yang // EMBO Journal;10/27/2004, Vol. 23 Issue 21, p4134 

    MutL assists the mismatch recognition protein MutS to initiate and coordinate mismatch repair in species ranging from bacteria to humans. The MutL N-terminal ATPase domain is highly conserved, but the C-terminal region shares little sequence similarity among MutL homologs. We report here the...

  • A case for sliding SeqA tracts at anchored replication forks during Escherichia coli chromosome replication and segregation. Brendler, Therese; Sawitzke, Jim; Sergueev, Kirill; Austin, Stuart // EMBO Journal;11/15/2000, Vol. 19 Issue 22, p6249 

    SeqA is an Escherichia coli DNA-binding protein that acts at replication origins and controls DNA replication. However, binding is not exclusive to origins. Many fragments containing two or more hemi-methylated GATC sequences bind efficiently. Binding was optimal when two such sequences were...

  • RuvAB is essential for replication forks reversal in certain replication mutants. Baharoglu, Zeynep; Petranovic, Mirjana; Flores, Maria-Jose; Michel, Bénédicte // EMBO Journal;2/8/2006, Vol. 25 Issue 3, p596 

    Inactivated replication forks may be reversed by the annealing of leading- and lagging-strand ends, resulting in the formation of a Holliday junction (HJ) adjacent to a DNA double-strand end. In Escherichia coli mutants deficient for double-strand end processing, resolution of the HJ by RuvABC...

  • RecG Protein and Single-Strand DNA Exonucleases Avoid Cell Lethality Associated With PriA Helicase Activity in Escherichia coli.  // Genetics;Oct2010, Vol. 186 Issue 2, p473 

    No abstract available.

  • A Role for Nonessential Domain II of Initiator Protein, DnaA, in Replication Control. Molt, Kathryn L.; Sutera Jr., Vincent A.; Moore, Kathryn K.; Lovett, Susan T. // Genetics;Sep2009, Vol. 183 Issue 1, p39 

    The initiation of replication in bacteria is regulated via the initiator protein DnaA. ATP-bound DnaA binds to multiple sequences at the origin of replication, oriG, unwinding the DNA and promoting the binding of DnaB helicase. From an Escherichia coli mutant highly perturbed for replication...

Share

Read the Article

Courtesy of VIRGINIA BEACH PUBLIC LIBRARY AND SYSTEM

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics