GO:0051539 4 iron, 4 sulfur cluster binding: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0051539 describes the molecular function of binding a 4Fe-4S cluster, a cofactor made of four iron and four inorganic sulfur atoms bridged between iron ions.
• 4Fe-4S clusters are ancient, versatile cofactors that enable electron transfer, substrate binding and activation, and regulatory sensing in proteins across all domains of life.
• Defects in 4Fe-4S cluster biogenesis and cluster-bearing proteins are linked to mitochondrial disease, neurodegeneration, cancer and viral replication.
• Key experimental models include knockout, point-mutation, knock-in and overexpression cell lines that probe cluster assembly, protein stability and catalytic activity.
• CRISPR screening and bioinformatics can systematically identify genes required for 4Fe-4S cluster-dependent pathways and their disease relevance.
• Studying GO:0051539 requires integrating structural, biochemical and genetic methods, from anaerobic spectroscopy to mitochondrial translation profiling.
Description
GO:0051539, 4 iron, 4 sulfur cluster binding, is a molecular function term that captures the ability of a protein to coordinate a 4Fe-4S cluster, a cofactor composed of four iron atoms and four inorganic sulfur atoms arranged so that the sulfur atoms bridge the iron ions. This binding event is not a passive interaction; it positions the cluster within a protein scaffold where it can accept or donate electrons, bind substrates, or sense environmental cues. Because 4Fe-4S clusters are chemically versatile and structurally conserved, they appear in enzymes, scaffolds, regulatory proteins and viral helicases, making GO:0051539 central to bioenergetics, metabolism and gene regulation. For researchers, GO:0051539 provides a precise annotation handle for proteins whose function depends on an intact 4Fe-4S cluster. Loss of cluster binding can destabilize the protein, abolish catalysis or disrupt signaling, and such defects have been connected to mitochondrial dysfunction, neurodegeneration and altered viral replication. Understanding which proteins bind 4Fe-4S clusters, how those clusters are assembled, and how binding is regulated is therefore essential for interpreting genetic variants and designing targeted experiments. This article synthesizes the QuickGO definition of GO:0051539 with verified PubMed literature to outline the mechanism, key genes, disease links and research methods relevant to 4 iron, 4 sulfur cluster binding. It is intended for scientists who need a publication-ready overview that can guide experimental design and data interpretation.
4 iron, 4 sulfur cluster binding At A Glance
| GO ID | GO:0051539 |
|---|---|
| GO term | 4 iron, 4 sulfur cluster binding |
| Ontology | molecular_function |
| Synonym | 4Fe-4S cluster binding; iron-sulfur cluster 4Fe-4S binding; tetrairon tetrasulfide cluster binding |
| Definition | Binding to a 4 iron, 4 sulfur (4Fe-4S) cluster; this cluster consists of four iron atoms, with the inorganic sulfur atoms found between the irons and acting as bridging ligands. |
| Major function | Enables proteins to coordinate a 4Fe-4S cofactor for electron transfer, substrate binding or regulatory sensing. |
| Cluster composition | Four iron atoms and four inorganic sulfur atoms, with sulfur bridging the iron ions. |
| Representative proteins | Fe-S scaffold proteins, mitochondrial translation factors, viral helicases and metabolic enzymes. |
| Disease relevance | Defects in 4Fe-4S cluster binding are associated with mitochondrial disease, neurodegeneration and altered viral replication. |
What Is GO:0051539?
In our own words, GO:0051539 (4 iron, 4 sulfur cluster binding) is the molecular function of selectively and non-covalently interacting with a 4Fe-4S cluster, a cofactor in which four iron atoms and four inorganic sulfur atoms are arranged so that the sulfur atoms bridge the iron ions. This binding typically occurs within a protein pocket that provides cysteine, histidine or other ligands to anchor the cluster, and it enables the protein to use the cluster for electron transfer, substrate activation or regulatory sensing.
Why Is 4 iron, 4 sulfur cluster binding Important in Cell Biology?
GO:0051539 matters because 4Fe-4S clusters are among the most ancient and versatile protein cofactors, and their binding underlies fundamental processes such as electron transport, mitochondrial translation, metabolic catalysis and viral RNA unwinding. When cluster binding is impaired, proteins can misfold or lose activity, contributing to human disease and altering cellular responses to stress.
• 4Fe-4S clusters are essential for electron transfer in respiratory and metabolic pathways.
• Cluster binding regulates the activity of enzymes and scaffold proteins involved in iron-sulfur biogenesis.
• Mitochondrial translation depends on 4Fe-4S cluster checkpoint proteins such as METTL17.
• Viral helicases, including SARS-CoV-2 helicase, can contain 4Fe-4S clusters that modulate RNA binding and unwinding.
• Loss of cluster binding is linked to mitochondrial dysfunction and neurodegeneration.
• Hypoxia can rescue defects caused by loss of frataxin, a key player in iron-sulfur cluster biogenesis.
• 4Fe-4S cluster binding is a target for understanding metal homeostasis and oxidative stress responses.
• CRISPR screens can identify genes required for 4Fe-4S cluster-dependent processes.
• Cluster-binding proteins are candidate drug targets in cancer and infectious disease.
• Studying GO:0051539 helps annotate uncharacterized proteins and interpret genomic variants.
Molecular Function of 4 iron, 4 sulfur cluster binding
Cluster coordination and protein scaffold
In simple terms: The protein provides a pocket that holds the 4Fe-4S cluster in place.
Binding of a 4Fe-4S cluster occurs when a protein scaffold presents ligands, often cysteine residues, that coordinate the four iron atoms while inorganic sulfur bridges the irons. This coordination stabilizes the cluster and positions it for function, as seen in scaffold proteins such as IscU that are required for activation of downstream targets like Fur in Escherichia coli. The structural integrity of the scaffold is therefore a prerequisite for GO:0051539 activity.
Electron transfer and substrate activation
In simple terms: The cluster can pass electrons or help break and form chemical bonds.
Once bound, a 4Fe-4S cluster can mediate electron transfer or participate directly in substrate activation. For example, dinitrogen binding and activation at a molybdenum-iron-sulfur cluster illustrates how iron-sulfur clusters can activate inert substrates. Similarly, heterometallic nickel-iron-sulfur clusters model substrate binding and cyanide inhibition of carbon monoxide dehydrogenase, showing that cluster chemistry extends to catalytic transformations.
Regulatory and sensing roles
In simple terms: Some proteins use the cluster as a sensor to switch activities on or off.
Beyond catalysis, 4Fe-4S clusters can act as regulatory modules. The scaffold protein IscU is required for activation of ferric uptake regulator (Fur) in Escherichia coli, linking cluster assembly to iron-responsive gene regulation. In mitochondria, METTL17 functions as an Fe-S cluster checkpoint for mitochondrial translation, coupling cluster status to protein synthesis. These examples show that GO:0051539 can be a regulatory node rather than only a catalytic feature.
Viral and host cluster-binding proteins
In simple terms: Viruses can also use 4Fe-4S clusters to control their own machinery.
The SARS-CoV-2 helicase contains an iron-sulfur cluster in its zinc-binding domain that modulates RNA-binding and unwinding activities. This demonstrates that GO:0051539 is relevant to viral replication and can be targeted for antiviral research. Host cluster biogenesis pathways may also influence viral infection by supplying or restricting cluster availability.
Photodynamic and chemical models
In simple terms: Synthetic clusters help researchers understand how natural clusters behave.
Model compounds such as nitrosyl iron-sulfur [Fe2S2(NO)4]2- clusters provide insight into photodynamic mechanisms and protein binding, helping to dissect the chemistry of iron-sulfur clusters. These chemical models complement biological studies of GO:0051539 by revealing how cluster composition and environment affect reactivity.
Key Genes Involved in GO:0051539 4 iron, 4 sulfur cluster binding
The following genes and proteins are representative of the machinery and targets associated with GO:0051539, 4 iron, 4 sulfur cluster binding, based on verified literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| FXN | Frataxin involved in iron-sulfur cluster biogenesis | Loss causes Friedreich ataxia; hypoxia rescues frataxin loss by restoring cluster biogenesis. |
| METTL17 | Mitochondrial translation factor acting as Fe-S cluster checkpoint | Links 4Fe-4S cluster status to mitochondrial protein synthesis. |
| ISCU | Iron-sulfur cluster assembly scaffold protein | Required for activation of Fur in E. coli; model for cluster assembly. |
| FUR | Ferric uptake regulator | Activated by IscU-dependent cluster assembly; iron-responsive regulator. |
| NIF | Nitrogenase components binding molybdenum-iron-sulfur clusters | Model for dinitrogen binding and activation at Fe-S clusters. |
| CODH | Carbon monoxide dehydrogenase | Heterometallic nickel-iron-sulfur cluster models substrate binding and cyanide inhibition. |
| SARS-CoV-2 helicase | Viral helicase with Fe-S cluster in zinc-binding domain | Cluster modulates RNA-binding and unwinding activities. |
| Fe-S cluster assembly proteins | General biogenesis machinery | Targets for understanding cluster delivery and protein maturation. |
| Mitochondrial translation factors | Translation machinery dependent on Fe-S clusters | Checkpoint control by METTL17. |
| Electron transfer proteins | Respiratory and metabolic electron carriers | Cluster binding enables redox reactions. |
| Regulatory proteins | Sensors of iron and oxidative stress | Cluster status can switch regulatory activity. |
| Model Fe-S compounds | Synthetic analogs | Used to study photodynamic mechanisms and protein binding. |
| Nickel-iron-sulfur enzymes | Catalytic metalloenzymes | Model substrate binding and inhibition. |
| Iron-sulfur scaffold complexes | Assembly and transfer | Central to GO:0051539 function. |
| Mitophagy regulators | Metabolite-controlled pathways | Endogenous metabolites regulate mitophagy, intersecting with Fe-S biology. |
How Is 4 iron, 4 sulfur cluster binding Regulated?
Regulation of 4Fe-4S cluster binding occurs at multiple levels, including cluster assembly, protein stability and cellular iron homeostasis. The scaffold protein IscU is required for activation of Fur in Escherichia coli, illustrating how cluster assembly controls downstream regulatory proteins. In mitochondria, METTL17 acts as an Fe-S cluster checkpoint for mitochondrial translation, coupling cluster availability to protein synthesis. Hypoxia can rescue frataxin loss by restoring iron-sulfur cluster biogenesis, indicating that oxygen tension regulates cluster formation. Additionally, endogenous metabolites can influence mitophagy, which intersects with iron-sulfur cluster-dependent mitochondrial quality control.
4 iron, 4 sulfur cluster binding and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| FXN | Friedreich ataxia; impaired Fe-S cluster biogenesis | Knockout and rescue with hypoxia in cell models |
| METTL17 | Mitochondrial translation defect; mitochondrial disease | Knockout and point-mutation cell lines |
| SARS-CoV-2 helicase | Viral replication; RNA unwinding | Overexpression and point-mutation in viral replicon systems |
| ISCU | Iron homeostasis dysregulation | Knockout in E. coli and mammalian cells |
| CODH | Carbon monoxide metabolism; cyanide inhibition | Enzyme assays with heterometallic cluster models |
Neurodegeneration and Friedreich ataxia
Loss of frataxin impairs iron-sulfur cluster biogenesis, and hypoxia rescues this defect by restoring cluster formation, linking GO:0051539 to neurodegenerative disease mechanisms. Defects in cluster binding can destabilize mitochondrial proteins and contribute to neuronal dysfunction.
Mitochondrial disease and translation defects
METTL17 functions as an Fe-S cluster checkpoint for mitochondrial translation, so disruption of 4Fe-4S cluster binding can impair mitochondrial protein synthesis and cause mitochondrial disease phenotypes. This connects GO:0051539 directly to mitochondrial ribosomopathy-like conditions.
Viral infection and antiviral targets
The SARS-CoV-2 helicase contains an iron-sulfur cluster that modulates its RNA-binding and unwinding activities, making GO:0051539 relevant to viral replication and antiviral drug discovery. Cluster-binding domains in viral proteins are potential targets for intervention.
Cancer and metabolic reprogramming
Iron-sulfur cluster proteins participate in metabolic and redox pathways that are rewired in cancer, and CRISPR screening can identify dependencies related to 4Fe-4S cluster binding. Understanding these dependencies may reveal therapeutic vulnerabilities.
From 4 iron, 4 sulfur cluster binding-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of a candidate gene impair 4Fe-4S cluster binding? | CRISPR knockout cell line followed by anaerobic spectroscopy |
| Does a specific residue coordinate the 4Fe-4S cluster? | Point-mutation knock-in of ligand residues |
| Can a disease-associated variant disrupt cluster binding? | Knock-in of patient variant and functional assays |
| Where does the cluster-bearing protein localize? | Tagged knock-in with fluorescent or affinity tag |
| Does overexpression rescue cluster deficiency? | Overexpression cell model |
| Which genes are required for cluster-dependent pathways? | CRISPR library screening and bioinformatics |
How to Study the 4 iron, 4 sulfur cluster binding Process
| Method | What It Measures | Typical Application |
|---|---|---|
| CRISPR knockout | Loss of gene function | Test requirement for 4Fe-4S cluster binding |
| Point mutation | Specific residue contribution | Identify cluster-coordinating ligands |
| Knock-in tagging | Protein localization and interactions | Track cluster-binding proteins in cells |
| Overexpression | Gain-of-function and rescue | Restore cluster biogenesis defects |
| CRISPR library screening | Genome-wide dependencies | Find genes required for cluster-dependent pathways |
| RNA-seq | Transcriptional changes | Measure cellular response to cluster loss |
| Proteomics | Protein abundance and interactions | Identify destabilized cluster proteins |
| Spectroscopy | Cluster presence and redox state | Confirm 4Fe-4S binding in vitro |
Genetic and biochemical assays
Knockout and point-mutation cell lines can test whether a gene is required for 4Fe-4S cluster binding and downstream function. Biochemical assays such as enzyme activity measurements and iron-sulfur cluster reconstitution can confirm cluster binding.
Spectroscopic and structural methods
Spectroscopic techniques including electron paramagnetic resonance and circular dichroism are used to detect 4Fe-4S clusters and assess their redox state. Structural studies of model compounds and proteins reveal cluster coordination geometry.
Omics and screening approaches
RNA-seq, proteomics and CRISPR library screening can identify genes and pathways dependent on 4Fe-4S cluster binding. Bioinformatics analysis of genomic and proteomic data helps prioritize cluster-binding candidates.
Imaging and mitochondrial function
Fluorescence imaging of tagged proteins and mitochondrial function assays can reveal how loss of cluster binding affects organelle dynamics and translation. Hypoxia rescue experiments can test whether cluster biogenesis is restored.
How CRISPR Can Be Used to Study GO:0051539 4 iron, 4 sulfur cluster binding
Knockout
CRISPR knockout of genes such as FXN or METTL17 can abolish 4Fe-4S cluster binding and reveal downstream phenotypes, including mitochondrial translation defects. Knockout models are useful for testing whether a candidate gene is essential for cluster-dependent processes.
Point Mutation
Point mutations in residues that coordinate the 4Fe-4S cluster can selectively disrupt binding without deleting the entire protein, allowing precise structure-function studies. Such models help distinguish loss of cluster binding from loss of protein expression.
Knock-in
Knock-in of disease-associated variants or tagged alleles enables researchers to study cluster binding in a physiological context. Tagged knock-in lines support imaging and proteomic analysis of cluster-binding proteins.
Overexpression
Overexpression of cluster assembly factors or target proteins can rescue defects caused by impaired 4Fe-4S cluster binding and help validate causal relationships. Overexpression models are also used to produce sufficient protein for biochemical and structural studies.
How EDITGENE Supports 4 iron, 4 sulfur cluster binding Research
Researchers studying 4 iron, 4 sulfur cluster binding-related genes often need to determine whether a candidate gene is causally involved in cluster assembly, protein stability or disease phenotypes. EDITGENE provides CRISPR-based cell models and screening services to accelerate this work.
Contact EDITGENE today to design your custom CRISPR model for 4 iron, 4 sulfur cluster binding research.
Frequently Asked Questions About 4 iron, 4 sulfur cluster binding
What is GO:0051539?
GO:0051539 is the molecular function term for 4 iron, 4 sulfur cluster binding, describing proteins that bind a 4Fe-4S cluster made of four iron and four inorganic sulfur atoms.
What genes are involved in 4 iron, 4 sulfur cluster binding?
Representative genes include FXN, METTL17, ISCU and FUR, as well as viral helicases such as the SARS-CoV-2 helicase.
Why is 4Fe-4S cluster binding important?
It enables electron transfer, substrate activation and regulatory sensing, and defects are linked to mitochondrial disease, neurodegeneration and viral replication.
How can I study 4Fe-4S cluster binding in cells?
Common approaches include CRISPR knockout, point mutation, knock-in tagging, overexpression, spectroscopy and CRISPR library screening.
What diseases are associated with 4Fe-4S cluster binding defects?
Friedreich ataxia, mitochondrial translation defects and viral infections are among the conditions linked to impaired cluster binding.
Can hypoxia affect 4Fe-4S cluster biogenesis?
Yes, hypoxia rescues frataxin loss by restoring iron-sulfur cluster biogenesis in experimental models.
What is the role of METTL17 in 4Fe-4S cluster binding?
METTL17 acts as an Fe-S cluster checkpoint for mitochondrial translation, coupling cluster status to protein synthesis.
How does the SARS-CoV-2 helicase use an iron-sulfur cluster?
Its iron-sulfur cluster in the zinc-binding domain modulates RNA-binding and unwinding activities.
What methods detect 4Fe-4S clusters?
Spectroscopic methods such as EPR and circular dichroism, along with biochemical reconstitution, are commonly used.
How can CRISPR screening help study 4Fe-4S cluster binding?
Genome-wide CRISPR screens can identify genes required for cluster-dependent pathways and reveal disease-relevant dependencies.
Conclusion
GO:0051539, 4 iron, 4 sulfur cluster binding, defines a fundamental molecular function that supports electron transfer, catalysis and regulation across diverse proteins. Its importance is underscored by links to neurodegeneration, mitochondrial disease and viral replication, making it a high-value target for mechanistic and therapeutic research. By combining CRISPR knockout, point-mutation, knock-in, overexpression and screening approaches with biochemical and omics methods, researchers can dissect how 4Fe-4S cluster binding contributes to health and disease. EDITGENE offers the cell models and bioinformatics support needed to accelerate these studies.
References
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