DnaG interacts with a linker region that joins the N- and C-domains of DnaB and induces the formation of 3-fold symmetric rings

Thirlway, Jenny and Turner, Ian J. and Gibson, Christopher T. and Gardiner, Laurence and Brady, Kevin and Allen, Stephanie and Roberts, Clive J. and Soultanas, Panos (2004) DnaG interacts with a linker region that joins the N- and C-domains of DnaB and induces the formation of 3-fold symmetric rings. Nucleic Acids Research, 32 (10). pp. 2977-2986. ISSN 0305-1048

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Abstract

Loading of the replicative ring helicase onto the origin of replication (oriC) is the final outcome of a well coordinated series of events that collectively constitute a primosomal cascade. Once the ring helicase is loaded, it recruits the primase and signals the switch to the polymerization mode. The transient nature of the helicase-primase (DnaB-DnaG) interaction in the Escherichia coli system has hindered our efforts to elucidate its structure and function. Taking advantage of the stable DnaB-DnaG complex in Bacillus stearothermophilus, we have reviewed conflicting mutagenic data from other bacterial systems and shown that DnaG interacts with the flexible linker that connects the N- and C-terminal domains of DnaB. Furthermore, atomic force microscopy (AFM) imaging experiments show that binding of the primase to the helicase induces predominantly a 3-fold symmetric morphology to the hexameric ring. Overall, three DnaG molecules appear to interact with the hexameric ring helicase but a small number of complexes with two and even one DnaG molecule bound to DnaB were also detected. The structural/functional significance of these data is discussed and a speculative structural model for this complex is suggested.

Item Type: Article
Schools/Departments: University of Nottingham UK Campus > Faculty of Science > School of Chemistry
Depositing User: Soultanas, Prof Panos
Date Deposited: 11 Aug 2009 12:02
Last Modified: 26 Aug 2014 17:01
URI: http://eprints.nottingham.ac.uk/id/eprint/1112

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