RepD-mediated recruitment of PcrA helicase at the Staphylococcus aureus pC221 plasmid replication origin, oriD

Machόn, Cristina and Thomson, N.H. and Lynch, G.P. and Scott, David J. and Thomas, C.D. and Soultanas, Panos (2010) RepD-mediated recruitment of PcrA helicase at the Staphylococcus aureus pC221 plasmid replication origin, oriD. Nucleic Acids Research, 38 (6). pp. 1874-1888. ISSN 0305-1048

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Abstract

Plasmid encoded replication initiation (Rep) proteins recruit host helicases to plasmid replication origins. Previously, we showed that RepD recruits directionally the PcrA helicase to the pC221 oriD, remains associated with it, and increases its processivity during plasmid unwinding. Here we show that RepD forms a complex extending upstream and downstream of the core oriD. Binding of RepD causes remodelling of a region upstream from the core oriD forming a 'landing pad' for the PcrA. PcrA is recruited by this extended RepD-DNA complex via an interaction with RepD at this upstream site. PcrA appears to have weak affinity for this region even in the absence of RepD. Upon binding of ADPNP (non-hydrolysable analogue of ATP), by PcrA, a conformational rearrangement of the RepD-PcrA-ATP initiation complex confines it strictly within the boundaries of the core oriD. We conclude that RepD-mediated recruitment of PcrA at oriD is a three step process. First, an extended RepD-oriD complex includes a region upstream from the core oriD; second, the PcrA is recruited to this upstream region and thirdly upon ATP-binding PcrA relocates within the core oriD.

Item Type: Article
Schools/Departments: University of Nottingham UK Campus > Faculty of Science > School of Chemistry
Depositing User: Soultanas, Prof Panos
Date Deposited: 02 Jun 2010 09:34
Last Modified: 26 Aug 2014 16:57
URI: http://eprints.nottingham.ac.uk/id/eprint/1312

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