Role of the Pif1-PCNA Complex in Pol δ-Dependent Strand Displacement DNA Synthesis and Break-Induced Replication.

Publication Type:

Journal Article

Source:

Cell Rep, Volume 21, Issue 7, p.1707-1714 (2017)

Abstract:

<p>The S.&nbsp;cerevisiae Pif1 helicase functions with DNA polymerase (Pol) δ in DNA synthesis during break-induced replication (BIR), a conserved pathway responsible for replication fork repair and telomere recombination. Pif1 interacts with the DNA polymerase processivity clamp PCNA, but the functional significance of the Pif1-PCNA complex remains to be elucidated. Here, we solve the crystal structure of PCNA in complex with a non-canonical PCNA-interacting motif in Pif1. The structure guides the construction of a Pif1 mutant that is deficient in PCNA interaction. This mutation impairs the ability of Pif1 to enhance DNA strand displacement synthesis by Pol δ in&nbsp;vitro and also the efficiency of BIR in cells. These results provide insights into the role of the Pif1-PCNA-Pol&nbsp;δ ensemble during DNA break repair by homologous recombination.</p>

PDB: 
6B8I
Detector: 
PILATUS
Beamline: 
24-ID-C