Genetics. Published Articles Ahead of Print: August 24, 2008, Copyright © 2008
doi:10.1534/genetics.108.089243


A more recent version of this article appeared on September 1, 2008.

REGULAR RESEARCH PAPERS

Rtf1-mediated eukaryotic site-specific replication termination

Trevor Eydmann 1, Elena Sommariva 1, Takabumi Inagawa 2, Saira Mian 3, Amar Klar 4 and Jacob Zeuthen Dalgaard 1*

1 Marie Curie Research Institute
2 University of Oxford
3 Lawrence Berkeley National Laboratory
4 National Cancer Institute

* To whom correspondence should be addressed. E-mail: j.dalgaard{at}mcri.ac.uk.

Submitted on March 18, 2008
Revised on April 29, 2008
Accepted on 30 June 2008


Abstract

The molecular mechanism mediating eukaryotic replication termination and pausing remains unknown. Here we present the molecular characterization of Rtf1 that mediates site-specific replication termination at the polar Schizosacharomyces pombe barrier RTS1. We show that Rtf1 possesses two chimeric myb/SANT domains, one is able to interact with the repeated motifs encoded by the RTS1 element as well as the elements enhancer region, while the other only show a weak DNA binding activity. In addition we show that C-terminal tail of Rtf1 mediates a self-interaction, and deletion of this tail has a dominant phenotype. Finally, we identify a point mutation in Rtf1 domain I that converts the RTS1 element into a replication barrier of the opposite polarity. Together our data establish that multiple protein-DNA and protein-protein interactions between Rtf1 molecules and both the repeated motifs and the enhancer region of RTS1 are required for site-specific termination at the RTS1 element.

Key Words: RTS1, Replication termination, Rtf1/TTF1/Reb1, Schizosacharomyces pombe