title: Structural studies of RFCCtf18reveal a novel chromatin recruitment role for Dcc1.
abstract: Replication factor C complexes load and unload processivity clamps from DNA and are involved in multiple DNA replication and repair pathways. The RFCCtf18variant complex is required for activation of the intra-S-phase checkpoint at stalled replication forks and aids the establishment of sister chromatid cohesion. Unlike other RFC complexes, RFCCtf18contains two non-Rfc subunits, Dcc1 and Ctf8. Here, we present the crystal structure of the Dcc1-Ctf8 heterodimer bound to the C-terminus of Ctf18. We find that the C-terminus of Dcc1 contains three-winged helix domains, which bind to both ssDNA and dsDNA We further show that these domains are required for full recruitment of the complex to chromatin, and correct activation of the replication checkpoint. These findings provide the first structural data on a eukaryotic seven-subunit clamp loader and define a new biochemical activity for Dcc1.
authors.affiliation: Structural Biology of Chromosome Segregation Laboratory, The Francis Crick Institute, London, UK.
authors.forename: Benjamin O
authors.initials: BO
authors.lastname: Wade
authors.affiliation: Chromosome Segregation Laboratory, The Francis Crick Institute, London, UK.
authors.forename: Hon Wing
authors.initials: HW
authors.lastname: Liu
authors.affiliation: Chromosome Segregation Laboratory, The Francis Crick Institute, London, UK.
authors.forename: Catarina P
authors.initials: CP
authors.lastname: Samora
authors.affiliation: Chromosome Segregation Laboratory, The Francis Crick Institute, London, UK.
authors.forename: Frank
authors.initials: F
authors.lastname: Uhlmann
authors.affiliation: Structural Biology of Chromosome Segregation Laboratory, The Francis Crick Institute, London, UK martin.singleton@crick.ac.uk.
authors.forename: Martin R
authors.identifier: 0000-0001-5716-7715
authors.initials: MR
authors.lastname: Singleton
mesh_terms: D000595:Amino Acid Sequence; D002843:Chromatin / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D011485:Protein Binding; D011487:Protein Conformation; D054730:Protein Interaction Domains and Motifs; D055503:Protein Multimerization; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000378:metabolism; D013329:Structure-Activity Relationship
chemical_list: C092693:CTF18 protein, S cerevisiae; D002843:Chromatin; D004268:DNA-Binding Proteins; C429769:Dcc1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins
keywords: Ctf18; Dcc1; S‐phase checkpoint; X‐ray crystallography; sister chromatid cohesion