Short article Molecular insight into the PCNA-binding mode of FBH1

F-box DNA helicase 1 (FBH1) is involved in the regulation of cell responses to replicative stress. FBH1 is recruited to stalled DNA replication fork by PCNA where it inhibits homologous recombination and catalyzes fork regression. Here, we report the structural basis for the molecular recognition of two distinctly different motifs of FBH1, FBH1PIP and FBH1APIM, by PCNA. The crystal structure of PCNA in complex with FBH1PIP and analysis of NMR perturbations reveal overlapped FBH1PIP and FBH1APIM binding sites of PCNA and the dominant contribution of FBH1PIP in this interaction.

Automated summary

FBH1 is involved in regulating cell responses to replicative stress and is recruited to stalled DNA replication forks by PCNA. It inhibits homologous recombination and catalyzes fork regression. This study reports the structural basis for the molecular recognition of two different motifs of FBH1 (FBH1PIP and FBH1APIM) by PCNA, revealing the overlapping binding sites of PCNA for FBH1PIP and FBH1APIM, with FBH1PIP making the dominant contribution to this interaction.