GO:0071821 FANCM-MHF complex: Components, Assembly and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0071821 defines the FANCM-MHF complex, a conserved eukaryotic protein complex containing FANCM and the histone-fold MHF1-MHF2 heterodimer that remodels DNA and protects replication forks.
• The complex is built from FANCM, a large DNA translocase, and MHF1 (also called CENPS) plus MHF2 (also called CENPX), which form a histone-fold heterodimer.
• MHF is remodeled by FANCM to recognize branched DNA structures such as replication forks and Holliday junctions, protecting genome stability.
• FANCM-MHF promotes replication traverse of DNA interstrand crosslinks, helping cells complete replication past lesions.
• In rice meiosis, FANCM interaction with MHF1-MHF2 limits crossover frequency, showing conserved meiotic functions.
• Structural and biochemical studies of the FANCM-MHF complex inform CRISPR models for studying DNA repair, replication stress, and cancer biology.
Description
The FANCM-MHF complex (GO:0071821) is a conserved eukaryotic protein assembly that contains the DNA translocase FANCM and the histone-fold MHF1-MHF2 heterodimer. It plays an essential role in DNA remodeling, protects replication forks, and is required for genome stability. Researchers study this complex because it sits at the intersection of DNA replication, interstrand crosslink repair, and meiotic recombination. The complex is defined in QuickGO as a protein complex containing FANCM and MHF, or their orthologs, conserved across eukaryotes. Structural work has revealed how MHF and FANCM assemble and how the complex engages branched DNA. Functional studies show that FANCM-MHF promotes replication traverse of DNA interstrand crosslinks, a key mechanism for completing replication under stress. In plants, the complex limits crossover frequency during meiosis, highlighting deep evolutionary conservation. Because of its roles in DNA repair and replication, the FANCM-MHF complex is a compelling target for cancer and genome stability research.
FANCM-MHF complex At A Glance
| GO ID | GO:0071821 |
|---|---|
| GO term | FANCM-MHF complex |
| Ontology | cellular_component |
| Synonym | None |
| Major function | DNA remodeling, replication fork protection, genome stability |
| Complex components | FANCM, MHF1 (CENPS), MHF2 (CENPX) |
| Conservation | Conserved in eukaryotes |
| Related processes | Interstrand crosslink repair, replication traverse, meiotic recombination |
| Structural feature | Histone-fold MHF heterodimer binds branched DNA |
What Is GO:0071821?
The FANCM-MHF complex is a multi-protein assembly that includes FANCM and the MHF histone-fold complex (MHF1-MHF2), or their orthologs, and functions in DNA remodeling, replication fork protection, and genome stability maintenance in eukaryotes. The MHF heterodimer binds DNA and is remodeled by FANCM to recognize branched DNA structures. The complex is conserved from yeast to humans and plants.
Why Is FANCM-MHF complex Important in Cell Biology?
The FANCM-MHF complex is important because it safeguards genome stability by protecting replication forks and promoting replication traverse of DNA interstrand crosslinks. Loss of FANCM-MHF function leads to sensitivity to DNA-damaging agents and defects in DNA repair, which are hallmarks of cancer predisposition and chemotherapeutic response. The complex also regulates meiotic crossover frequency, influencing genetic diversity in crops and potentially in humans. Understanding its structure and assembly informs drug discovery and CRISPR-based disease modeling.
• Protects replication forks from collapse during DNA replication stress.
• Promotes replication traverse of DNA interstrand crosslinks, enabling completion of replication past lesions.
• Maintains genome stability by recognizing and remodeling branched DNA structures.
• Limits crossover frequency during meiosis in rice, affecting genetic recombination.
• Is conserved across eukaryotes, making model organisms relevant for human studies.
• Mutations in FANCM and MHF components are linked to cancer predisposition and Fanconi anemia-like phenotypes.
• Serves as a target for understanding chemoresistance to crosslinking agents.
• Provides a model for studying histone-fold complex-DNA interactions.
• Structural insights enable design of inhibitors or probes.
• Relevant to CRISPR screens for DNA repair and replication genes.
Structure and Composition of FANCM-MHF complex
FANCM: The DNA Translocase Engine
In simple terms: FANCM is the motor protein that uses energy to move along DNA and remodel it.
FANCM is a large, conserved DNA translocase that forms the catalytic core of the FANCM-MHF complex. It contains helicase-like domains and an ERCC4-like nuclease domain, although its primary role in this complex is DNA remodeling rather than cleavage. FANCM interacts directly with MHF1-MHF2 to form a stable complex. Structural studies of the chicken FANCM-MHF complex reveal how FANCM binds MHF and how the complex is stabilized. Disulfide engineering studies further probe the constraints on crosslink design in this symmetric oligomer.
MHF1-MHF2: The Histone-Fold DNA-Binding Module
In simple terms: MHF1 and MHF2 are small proteins that together look like a histone pair and grab onto DNA.
MHF1 (CENPS) and MHF2 (CENPX) form a heterodimer with a histone-fold structure that binds DNA. The (MHF1-MHF2)4 octamer provides a long DNA binding patch that anchors the MHF-FANCM complex to chromatin, as shown by solution SAXS studies. MHF is remodeled by FANCM to recognize branched DNA structures such as replication forks and Holliday junctions. This remodeling is essential for protecting genome stability.
Assembly of the FANCM-MHF Complex
In simple terms: FANCM and MHF come together in a specific way to form a working machine.
The structure of the FANCM-MHF complex reveals physical features for functional assembly, including interfaces between FANCM and the MHF heterodimer. The complex is conserved in eukaryotes, and orthologs in chicken and other species have been structurally characterized. Disulfide engineering studies highlight constraints on crosslink design in symmetric oligomers, providing insights into assembly. The MHF octamer anchors the complex to chromatin via a long DNA binding patch.
DNA Binding and Remodeling by the Complex
In simple terms: The complex grabs branched DNA and changes its shape to protect it.
FANCM-MHF binds branched DNA structures and remodels them to protect replication forks. The complex promotes replication traverse of DNA interstrand crosslinks, allowing replication to continue past lesions. In rice meiosis, FANCM interacts with MHF1-MHF2 to limit crossover frequency, demonstrating a role in recombination. These activities depend on the histone-fold DNA-binding surface of MHF and the translocase activity of FANCM.
Key Genes Involved in GO:0071821 FANCM-MHF complex
The following genes and proteins are core components or direct interactors of the FANCM-MHF complex, based on published literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| FANCM | DNA translocase, catalytic core of the complex | Central to DNA remodeling and replication fork protection |
| MHF1 (CENPS) | Histone-fold subunit, DNA binding | Essential for complex assembly and branched DNA recognition |
| MHF2 (CENPX) | Histone-fold subunit, DNA binding | Partners with MHF1 to form the MHF heterodimer |
| FANCM orthologs (chicken) | Structural model for complex assembly | Used in crystallography and stability studies |
| MHF1-MHF2 octamer | Long DNA binding patch | Anchors complex to chromatin |
| FANCM-MHF in rice | Meiotic crossover regulation | Limits crossover frequency during meiosis |
| FANCM-MHF in yeast | Conserved DNA repair complex | Model for genome stability studies |
| FANCM-MHF in humans | Replication fork protection | Relevant to cancer and Fanconi anemia |
| FANCM-MHF complex | Replication traverse of ICLs | Promotes replication past crosslinks |
| MHF1 | Histone-fold complex subunit | Remodeled by FANCM for branched DNA recognition |
| MHF2 | Histone-fold complex subunit | Required for complex stability |
| FANCM | Interacts with MHF1-MHF2 | Physical assembly interface |
| FANCM-MHF | Disulfide engineering target | Probes crosslink design constraints |
| MHF1-MHF2 | SAXS structural studies | Reveals octameric DNA binding patch |
| FANCM | DNA translocase activity | Drives DNA remodeling |
| MHF | Histone-fold DNA binding | Recognizes branched DNA |
| FANCM-MHF | Genome stability maintenance | Protects replication forks |
How Is FANCM-MHF complex Regulated?
The FANCM-MHF complex is regulated at multiple levels. Its assembly depends on the availability of MHF1 and MHF2, which form a histone-fold heterodimer that is remodeled by FANCM to recognize branched DNA. Post-translational modifications and protein-protein interactions may influence complex stability, as suggested by structural and disulfide engineering studies. In meiosis, the complex is regulated to limit crossover frequency, likely through interaction with recombination machinery. However, specific upstream regulators such as mTOR or ISR are not documented for this complex in the provided literature.
FANCM-MHF complex and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| FANCM | Cancer predisposition, Fanconi anemia | Knockout cell lines, mouse models |
| MHF1 (CENPS) | Genome instability, cancer | Knockout and point-mutation cell models |
| MHF2 (CENPX) | Genome instability, cancer | Knockout and overexpression models |
| FANCM-MHF complex | Replication stress, chemoresistance | Knock-in tagged lines, CRISPR screens |
| FANCM orthologs | Meiotic recombination defects | Rice and plant models |
Cancer and Genome Instability
Defects in FANCM-MHF complex function lead to impaired DNA repair and replication fork protection, contributing to genome instability that is a hallmark of cancer. FANCM mutations are associated with cancer predisposition and sensitivity to DNA crosslinking agents. The complex promotes replication traverse of interstrand crosslinks, and its loss can lead to chemoresistance or sensitivity depending on context.
Fanconi Anemia and Bone Marrow Failure
FANCM is a component of the Fanconi anemia DNA repair pathway, and MHF1-MHF2 are required for its function. Disruption of the FANCM-MHF complex can lead to Fanconi anemia-like phenotypes, including bone marrow failure and developmental abnormalities. The complex is essential for protecting replication forks, and its loss exacerbates DNA damage.
Meiotic Defects and Infertility
In rice, FANCM interaction with MHF1-MHF2 limits crossover frequency during meiosis, and disruption leads to meiotic defects. This suggests that the complex is important for fertility and genetic recombination in plants, with potential parallels in mammals.
From FANCM-MHF complex-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does FANCM loss affect replication fork protection? | FANCM knockout cell lines |
| How does MHF1-MHF2 bind branched DNA? | Point mutations in MHF1/MHF2 DNA-binding surface |
| What is the effect of a cancer-associated FANCM mutation? | Knock-in of patient-derived mutations |
| Where does the complex localize during replication stress? | Tagged knock-in of FANCM or MHF1 |
| Does overexpression of MHF1-MHF2 alter genome stability? | Overexpression cell models |
| Which genes synthetically interact with FANCM-MHF? | CRISPR library screening |
How to Study the FANCM-MHF complex Process
| Method | What It Measures | Typical Application |
|---|---|---|
| X-ray crystallography | 3D structure of FANCM-MHF | Assembly interface mapping |
| SAXS | Solution shape of MHF octamer | DNA binding patch identification |
| Disulfide engineering | Crosslink constraints in oligomers | Complex stability studies |
| DNA remodeling assays | Branched DNA processing | FANCM-MHF function |
| Replication traverse assay | ICL traverse activity | Interstrand crosslink repair |
| DNA fiber assay | Replication fork progression | Replication stress response |
| CRISPR knockout | Gene function loss | Genome stability studies |
| CRISPR library screening | Synthetic lethal interactions | DNA repair pathway discovery |
Structural Biology (Crystallography, SAXS, Crosslinking)
Structural studies of the FANCM-MHF complex have used X-ray crystallography, solution SAXS, and disulfide engineering to reveal assembly interfaces and DNA-binding patches. These methods provide high-resolution insights into how the complex recognizes branched DNA.
Biochemical Assays for DNA Remodeling
DNA remodeling and replication traverse assays measure the ability of FANCM-MHF to process branched DNA and interstrand crosslinks. Electrophoretic mobility shift assays and helicase/translocase assays are commonly used.
Cell-Based Imaging and Replication Fork Analysis
Imaging of tagged FANCM or MHF1 in cells, combined with DNA fiber assays, reveals replication fork protection and traverse activity. These methods are used to study replication stress responses.
Genome Editing and Functional Genomics
CRISPR knockout, point mutation, and knock-in models are used to dissect the function of FANCM-MHF components in DNA repair and genome stability. CRISPR library screening can identify synthetic lethal interactions.
How CRISPR Can Be Used to Study GO:0071821 FANCM-MHF complex
Knockout
CRISPR knockout of FANCM, MHF1, or MHF2 disrupts the FANCM-MHF complex, leading to replication fork instability and sensitivity to DNA crosslinking agents. These models are used to study genome stability and DNA repair.
Point Mutation
Point mutations in the DNA-binding surface of MHF1 or MHF2, or in the FANCM translocase domain, can be introduced to dissect specific functions such as branched DNA recognition and replication traverse. These models help separate DNA binding from catalytic activity.
Knock-in
Knock-in of tagged FANCM or MHF1 (e.g., GFP or HA) allows localization and interaction studies in live cells. Knock-in of patient-derived mutations can model disease-associated variants.
Overexpression
Overexpression of MHF1-MHF2 or FANCM can be used to test gain-of-function effects on genome stability and replication fork protection. These models are useful for biochemical purification of the complex.
How EDITGENE Supports FANCM-MHF complex Research
Researchers studying FANCM-MHF complex-related genes often need to determine whether a candidate gene is causally involved in DNA repair, replication fork protection, or genome stability. EDITGENE provides CRISPR-based cell models and screening services to accelerate this research.
Contact EDITGENE today to design your custom CRISPR model for FANCM-MHF complex research.
Frequently Asked Questions About FANCM-MHF complex
What is the FANCM-MHF complex?
The FANCM-MHF complex (GO:0071821) is a conserved eukaryotic protein complex containing FANCM and the MHF1-MHF2 histone-fold heterodimer that remodels DNA and protects replication forks.
What genes are involved in the FANCM-MHF complex?
The core genes are FANCM, MHF1 (CENPS), and MHF2 (CENPX), which assemble into the complex.
What is the function of GO:0071821?
GO:0071821 defines a protein complex that plays an essential role in DNA remodeling, protects replication forks, and is conserved in eukaryotes.
How does the FANCM-MHF complex protect replication forks?
It binds branched DNA and promotes replication traverse of DNA interstrand crosslinks, preventing fork collapse.
What diseases are associated with FANCM-MHF complex defects?
Defects are linked to cancer predisposition, Fanconi anemia, and genome instability.
What is the structure of the FANCM-MHF complex?
It consists of FANCM, a DNA translocase, and the MHF1-MHF2 histone-fold heterodimer, which forms an octamer with a long DNA binding patch.
Is the FANCM-MHF complex conserved?
Yes, it is conserved in eukaryotes, including humans, chickens, yeast, and rice.
How is the FANCM-MHF complex studied?
Common methods include X-ray crystallography, SAXS, DNA remodeling assays, and CRISPR knockout models.
What is the role of MHF1 and MHF2?
MHF1 and MHF2 form a histone-fold heterodimer that binds DNA and is remodeled by FANCM to recognize branched DNA.
Can CRISPR be used to study FANCM-MHF complex?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression models are widely used to dissect its functions.
Conclusion
The FANCM-MHF complex (GO:0071821) is a conserved DNA-remodeling machine essential for replication fork protection and genome stability. Its core components FANCM, MHF1, and MHF2 assemble into a structure that recognizes branched DNA and promotes replication traverse of interstrand crosslinks. Studying this complex with CRISPR models and structural methods provides insights into cancer, Fanconi anemia, and meiotic recombination. EDITGENE offers comprehensive CRISPR services to support research on FANCM-MHF complex-related genes.
References
- 1. Ito S et al.. 2021. Structural analysis of the chicken FANCM-MHF complex and its stability.. Acta Crystallogr F Struct Biol Commun 77(Pt 1):1-7 PMID: 33439149
- 2. Tao Y et al.. 2012. The structure of the FANCM-MHF complex reveals physical features for functional assembly.. Nat Commun 3:782 PMID: 22510687
- 3. Ito S et al.. 2026. Disulfide engineering of the FANCM-MHF complex reveals constraints on crosslink design in symmetric oligomers.. Protein Sci 35(9):e70761 PMID: 42606197
- 4. Fox D 3rd et al.. 2014. The histone-fold complex MHF is remodeled by FANCM to recognize branched DNA and protect genome stability.. Cell Res 24(5):560-75 PMID: 24699063
- 5. Wang W et al.. 2013. Structural peculiarities of the (MHF1-MHF2)4 octamer provide a long DNA binding patch to anchor the MHF-FANCM complex to chromatin: a solution SAXS study.. FEBS Lett 587(18):2912-7 PMID: 23886707
- 6. Li Y et al.. 2023. FANCM interacts with the MHF1-MHF2 complex to limit crossover frequency during rice meiosis.. Plant J 116(3):717-727 PMID: 37632767
- 7. Yan Z et al.. 2010. A histone-fold complex and FANCM form a conserved DNA-remodeling complex to maintain genome stability.. Mol Cell 37(6):865-78 PMID: 20347428
- 8. Huang J et al.. 2013. The DNA translocase FANCM/MHF promotes replication traverse of DNA interstrand crosslinks.. Mol Cell 52(3):434-46 PMID: 24207054
