The fork protection complex recruits FACT to reorganize nucleosomes during replication

Nucleic Acids Res. 2022 Feb 22;50(3):1317-1334. doi: 10.1093/nar/gkac005.

Abstract

Chromosome replication depends on efficient removal of nucleosomes by accessory factors to ensure rapid access to genomic information. Here, we show this process requires recruitment of the nucleosome reorganization activity of the histone chaperone FACT. Using single-molecule FRET, we demonstrate that reorganization of nucleosomal DNA by FACT requires coordinated engagement by the middle and C-terminal domains of Spt16 and Pob3 but does not require the N-terminus of Spt16. Using structure-guided pulldowns, we demonstrate instead that the N-terminal region is critical for recruitment by the fork protection complex subunit Tof1. Using in vitro chromatin replication assays, we confirm the importance of these interactions for robust replication. Our findings support a mechanism in which nucleosomes are removed through the coordinated engagement of multiple FACT domains positioned at the replication fork by the fork protection complex.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • DNA Replication
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism
  • High Mobility Group Proteins / metabolism
  • Nucleosomes* / genetics
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae Proteins* / genetics
  • Saccharomyces cerevisiae Proteins* / metabolism
  • Transcription Factors / genetics
  • Transcriptional Elongation Factors / genetics

Substances

  • DNA-Binding Proteins
  • FACT protein, S cerevisiae
  • High Mobility Group Proteins
  • Nucleosomes
  • Saccharomyces cerevisiae Proteins
  • Transcription Factors
  • Transcriptional Elongation Factors