Pif1 family helicases have multiple roles in the maintenance of nuclear and mitochondrial DNA in eukaryotes. Saccharomyces cerevisiae Pif1 is involved in replication through barriers to replication, such as G-quadruplexes and protein blocks, and reduces genetic instability at these sites. Another Pif1 family helicase in S. cerevisiae, Rrm3, assists in fork progression through replication fork barriers at the rDNA locus and tRNA genes. ScPif1 (Saccharomyces cerevisiae Pif1) also negatively regulates telomerase, facilitates Okazaki fragment processing, and acts with polymerase δ in break-induced repair. Recent crystal structures of bacterial Pif1 helicases and the helicase domain of human PIF1 combined with several biochemical and biological studies on the activities of Pif1 helicases have increased our understanding of the function of these proteins. This review article focuses on these structures and the mechanism(s) proposed for Pif1's various activities on DNA.
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October 2017
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Cover Image
Cover Image
The Holliday junction. The structure of the Holliday junction is highly variable, being adaptable to its biological function in recombination and to applications in biomolecular engineering. This image shows the how the junction extends from simple schematics to crystal structures as DNA only and in protein complexes. In addition, the junction has been exploited as an element in the design of 2-D and 3-D lattices in crystal engineering and more complex images and shapes through DNA origami. In this issue of Biochemical Society Transactions, P. Shing Ho reviews some interesting recent research on the Holliday junction; for details see pages 1149–1158.
Review Article|
September 12 2017
Structure and function of Pif1 helicase
Biochem Soc Trans (2017) 45 (5): 1159–1171.
Article history
Received:
July 04 2017
Revision Received:
August 10 2017
Accepted:
August 11 2017
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