Evidence map›Paper›PMID 41730002›Full record

ArticleeLife2026

Structure of the human CTF18-RFC clamp loader bound to PCNA.

Giuseppina R Briola, Mohammad Tehseen, Amani Al-Amodi, Grace Young, Ammar U Danazumi, Phong Quoc Nguyen, Christos G Savva, Mark Hedglin, Samir M Hamdan, Alfredo De Biasio

Abstract read
In one paragraph

Article in eLife, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 4 papers.

0numbers the graph read from it
0cells of the map it votes in
4citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

4 citing papers in PubMed.

  1. Mechanistic diversity of clamp loading at small DNA gaps.The Journal of biological chemistry · 2026
    Review
  2. Article
  3. PCNA is a nucleotide exchange factor for the clamp loader ATPase complex.Proceedings of the National Academy of Sciences of the United States of America · 2025
    Article
  4. PCNA is a Nucleotide Exchange Factor for the Clamp Loader ATPase Complex.bioRxiv : the preprint server for biology · 2025
    Article
4 · The record

Corrections and comments

5 · Who and what money

Authors and funding

10 authors.

Giuseppina R Briola *Bioscience Program, Division of Biomedical Sciences, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia.
Mohammad Tehseen *Bioscience Program, Division of Biomedical Sciences, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia.
Amani Al-AmodiBioscience Program, Division of Biomedical Sciences, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia.
Grace YoungDepartment of Chemistry, The Pennsylvania State University, University Park, United States.
Ammar U DanazumiBioscience Program, Division of Biomedical Sciences, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia.
Phong Quoc NguyenBioscience Program, Division of Biomedical Sciences, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia.ORCID https://orcid.org/0000-0001-5968-9170
Christos G SavvaBioscience Program, Division of Biomedical Sciences, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia.
Mark HedglinDepartment of Chemistry, The Pennsylvania State University, University Park, United States.ORCID https://orcid.org/0000-0003-2599-1691
Samir M HamdanBioscience Program, Division of Biomedical Sciences, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia.ORCID https://orcid.org/0000-0001-5192-1852
Alfredo De BiasioBioscience Program, Division of Biomedical Sciences, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia.ORCID https://orcid.org/0000-0003-2139-2958

Funding

Deciphering the progression and regulation of human translesion DNA synthesisR35GM147238 · NIGMS · PENNSYLVANIA STATE UNIV HERSHEY MED CTR · PI Mark Hedglin · 2022 to 2026
$2.0M
Molecular Machines Mechanism and Structure (M3S) Training ProgramT32GM149417 · NIGMS · PENNSYLVANIA STATE UNIVERSITY, THE · PI William Olaf Hancock · 2023 to 2026
$1.8M
NIGMS NIH HHS R35 GM147238NIGMS NIH HHS T32 GM149417NIH HHS R35 GM147238-03NIH HHS T32GM149417
6 · The paper itself

Abstract

Sliding clamps like PCNA are crucial processivity factors for replicative polymerases, requiring specific clamp loaders for loading onto DNA. The human alternative clamp loader CTF18-RFC interacts with the leading strand polymerase Pol ε and loads PCNA onto primer/template DNA using its RFC pentameric module. Here, we provide a structural characterization of the human CTF18-RFC complex and its interaction with PCNA. Our cryo-EM data support that the Ctf8 and Dcc1 subunits of CTF18-RFC, which form the regulatory module interacting with Pol ε, are flexibly tethered to the RFC module. A 2.9 Å cryo-EM structure shows the RFC module bound to PCNA in an autoinhibited conformation similar to the canonical RFC loader, marking the initial step of the clamp-loading reaction. The unique RFC1 (Ctf18) large subunit of CTF18-RFC, which based on the cryo-EM map shows high relative flexibility, is anchored to PCNA through an atypical low-affinity PIP box in the AAA+ domain and engages the RFC5 subunit using a novel β-hairpin at the disordered N-terminus. We show that deletion of this β-hairpin impairs the CTF18-RFC-PCNA complex stability, slows down clamp loading, and decreases the rate of primer synthesis by Pol ε. Our research identifies distinctive structural characteristics of the human CTF18-RFC complex, providing insights into its role in PCNA loading and the stimulation of leading strand synthesis by Pol ε.

Indexed as

Proliferating Cell Nuclear AntigenReplication Protein CCryoelectron MicroscopyHumansModels, MolecularProtein BindingProtein ConformationPCNA protein, humanProliferating Cell Nuclear AntigenReplication Protein CRFC1 protein, humanclamp loaderscryo-EMDNA replicationhumanmolecular biophysicsPCNAsliding clampsstructural biology

Identifiers

PMID41730002
PMCPMC12928700

What OpenQuestion holds

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LicenceCC BY
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Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.