GO:0051536 iron-sulfur cluster binding: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0051536 iron-sulfur cluster binding is a molecular function describing the binding of iron-sulfur (Fe-S) clusters, combinations of iron and sulfur atoms, by proteins.
• Fe-S clusters are ancient, versatile cofactors that support electron transfer, catalysis, iron homeostasis, and regulatory sensing in mitochondria, cytosol, and bacteria.
• Mitochondrial Fe-S cluster assembly is a multi-step process involving the core complex, ferredoxin-2, and a dedicated chaperone-cochaperone system.
• Fe-S cluster biogenesis is tightly regulated by feedback mechanisms that sense cluster demand and iron availability.
• Dysfunction of Fe-S cluster binding proteins is linked to vascular biology, fungal iron regulation, zinc toxicity, and magnetic sensing.
• CRISPR-based knockout, point mutation, knock-in, and overexpression models enable causal dissection of Fe-S cluster binding genes in human cells and microbes.
Description
Iron-sulfur (Fe-S) clusters are among the most ancient and versatile protein cofactors in biology. The Gene Ontology term GO:0051536, iron-sulfur cluster binding, defines the molecular function of binding to a combination of iron and sulfur atoms. This function is executed by hundreds of proteins across all domains of life, where Fe-S clusters participate in electron transfer, substrate binding and catalysis, iron sensing, and regulation of gene expression. In eukaryotes, mitochondrial Fe-S cluster assembly is essential for the maturation of respiratory chain complexes, lipoic acid synthase, and numerous other Fe-S proteins. In bacteria such as Escherichia coli, Fe-S cluster biogenesis is intimately connected to intracellular iron homeostasis and stress responses. The study of Fe-S cluster binding has therefore become a central topic in cell biology, microbiology, and human disease research.
iron-sulfur cluster binding At A Glance
| GO ID | GO:0051536 |
|---|---|
| GO term | iron-sulfur cluster binding |
| Ontology | molecular_function |
| Synonym | Fe/S binding; iron sulfur cluster binding; iron sulphur cluster binding; iron-sulphur cluster binding |
| Major function | Binding to iron-sulfur clusters, enabling electron transfer, catalysis, and regulatory sensing |
| Cluster types | [2Fe-2S], [4Fe-4S], [3Fe-4S] and related forms |
| Cellular locations | Mitochondria, cytosol, nucleus, and bacterial cytoplasm |
| Representative proteins | Ferredoxin-2, ISCU, NFS1, ATE1, MagR |
| Related processes | Fe-S cluster assembly, iron homeostasis, oxidative stress response |
What Is GO:0051536?
GO:0051536 iron-sulfur cluster binding is a molecular function term defined as binding to an iron-sulfur cluster, a combination of iron and sulfur atoms. Fe-S clusters typically consist of iron and inorganic sulfide in various stoichiometries, such as [2Fe-2S], [4Fe-4S], and [3Fe-4S], and are coordinated by cysteine or other residues within proteins. This binding function underlies the ability of Fe-S proteins to perform electron transfer, catalysis, and regulatory roles.
Why Is iron-sulfur cluster binding Important in Cell Biology?
Iron-sulfur cluster binding is fundamental to life because Fe-S clusters are required for essential processes including mitochondrial respiration, DNA repair, ribosome biogenesis, and metabolic catalysis. Defects in Fe-S cluster biogenesis or binding cause severe human disorders, and Fe-S proteins are emerging as key players in vascular biology and iron-related diseases. In microorganisms, Fe-S cluster binding proteins regulate iron uptake and storage, and their dysfunction leads to sensitivity to metals such as zinc. Understanding this function is therefore critical for basic biology and therapeutic development.
• Fe-S clusters are essential cofactors for mitochondrial respiratory complexes and metabolic enzymes.
• Mitochondrial Fe-S cluster assembly is a conserved multi-step pathway involving the core complex and ferredoxin-2.
• Fe-S cluster binding proteins regulate intracellular iron homeostasis in bacteria and fungi.
• Zinc toxicity interferes with Fe-S cluster biogenesis in Escherichia coli.
• The ATE1 arginyltransferase requires an Fe-S cluster for its activity, linking Fe-S binding to protein degradation.
• MagR is a magnetosensitive protein whose properties are modulated by Fe-S cluster binding.
• Feedback regulation of Fe-S cluster biogenesis ensures balanced cluster production and iron utilization.
• Dysregulation of Fe-S cluster binding is implicated in vascular dysfunction and disease.
• Fe-S cluster binding is a target for antimicrobial and anticancer strategies.
• CRISPR models allow functional interrogation of Fe-S cluster binding genes in diverse cell types.
Molecular Mechanism of iron-sulfur cluster binding
Cluster types and coordination
In simple terms: Iron and sulfur atoms come together in different arrangements that proteins can hold.
Fe-S clusters exist in several forms, including [2Fe-2S], [4Fe-4S], and [3Fe-4S], each with distinct electronic properties. Proteins bind these clusters through cysteine residues or other ligands, and the cluster type determines the protein's function, such as electron transfer or catalysis.
Mitochondrial Fe-S cluster assembly
In simple terms: Mitochondria build Fe-S clusters step by step using a dedicated protein machinery.
Mitochondrial Fe-S cluster assembly begins with the core complex, where ferredoxin-2 binds in a two-stage manner to facilitate sulfur transfer. The core complex includes NFS1, ISCU, and other components that assemble the cluster before it is transferred to target proteins.
Bacterial Fe-S cluster biogenesis and iron homeostasis
In simple terms: Bacteria make Fe-S clusters and use them to sense and control iron levels.
In Escherichia coli, Fe-S cluster biogenesis is regulated by iron availability and feedback mechanisms that adjust cluster production. Fe-S cluster binding proteins such as those in the ISC system control intracellular iron homeostasis, and disruptions lead to zinc toxicity.
Regulatory roles of Fe-S cluster binding
In simple terms: Fe-S clusters can act as sensors that switch protein activity on or off.
Fe-S cluster binding is used in regulatory proteins that sense iron, oxygen, or oxidative stress. In fungi, Fe-S cluster signaling is a common thread in iron regulation, and in bacteria, Fe-S proteins control iron homeostasis. Feedback regulation of Fe-S cluster biogenesis ensures that cluster production matches demand.
Specialized Fe-S proteins and their functions
In simple terms: Some proteins use Fe-S clusters for unusual tasks like magnetic sensing or protein modification.
The ATE1 arginyltransferase requires an Fe-S cluster for its catalytic activity, linking Fe-S binding to post-translational protein modification. MagR is a magnetosensitive protein whose magnetic properties are modulated by Fe-S cluster binding. These examples highlight the functional diversity of Fe-S cluster binding.
Key Genes Involved in GO:0051536 iron-sulfur cluster binding
The following genes and proteins are representative of the iron-sulfur cluster binding function and its associated assembly machinery.
| Gene | Major Role | Research Relevance |
|---|---|---|
| NFS1 | Cysteine desulfurase providing sulfur for Fe-S cluster assembly | Core component of mitochondrial Fe-S cluster biogenesis |
| ISCU | Scaffold protein for Fe-S cluster assembly | Central to cluster assembly and transfer |
| FDX2 | Ferredoxin-2, electron donor for Fe-S cluster assembly | Two-stage binding to core complex |
| ISCU | Iron-sulfur cluster assembly scaffold | Mutations linked to disease |
| ATE1 | Arginyltransferase with Fe-S cluster | Fe-S cluster reconstitution studies |
| MagR | Magnetosensitive protein with Fe-S cluster | Magnetic properties modulated by cluster binding |
| ISC system genes (E. coli) | Fe-S cluster biogenesis and iron homeostasis | Model for bacterial Fe-S cluster regulation |
| SUF system genes | Fe-S cluster assembly under stress | Alternative assembly pathway |
| NfuA | Fe-S cluster carrier protein | Involved in cluster transfer |
| ErpA | Fe-S cluster carrier | Essential for Fe-S protein maturation |
| IscR | Fe-S cluster-containing regulator | Controls iron homeostasis and Fe-S biogenesis |
| FNR | Fe-S cluster-containing transcription factor | Oxygen sensing in bacteria |
| Aconitase | Fe-S cluster enzyme in TCA cycle | Model Fe-S protein |
| SDH | Succinate dehydrogenase with Fe-S clusters | Respiratory chain component |
| Complex I | NADH dehydrogenase with Fe-S clusters | Mitochondrial respiration |
| Lipoic acid synthase | Fe-S cluster enzyme for lipoic acid synthesis | Mitochondrial metabolism |
| Glutamine phosphoribosylpyrophosphate amidotransferase | Fe-S cluster enzyme in purine synthesis | Metabolic role |
| Rad3 | Fe-S cluster helicase in DNA repair | Genome stability |
How Is iron-sulfur cluster binding Regulated?
Fe-S cluster biogenesis and binding are regulated at multiple levels. In bacteria, feedback regulation of Fe-S cluster biogenesis adjusts production to match demand and iron availability. The IscR regulator, which contains an Fe-S cluster, controls expression of the ISC operon and iron homeostasis genes. In fungi, Fe-S cluster signaling is a common thread in iron regulation, linking cluster status to transcriptional responses. In mitochondria, ferredoxin-2 binding to the core complex is a regulated step in cluster assembly. These regulatory mechanisms ensure that Fe-S cluster binding proteins are produced and matured appropriately under varying conditions.
iron-sulfur cluster binding and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| FDX2 | Mitochondrial Fe-S cluster assembly defects | Knockout in human cell lines |
| ISCU | Fe-S cluster assembly and disease | Point mutation knock-in |
| ATE1 | Protein arginylation linked to Fe-S cluster | Overexpression and reconstitution |
| MagR | Magnetic sensing and Fe-S cluster binding | Knock-in of tagged MagR |
| IscR | Bacterial iron homeostasis and virulence | Knockout in E. coli |
Fe-S clusters in vascular biology and disease
Mitochondrial Fe-S clusters play an emerging role in vascular biology, and their dysfunction is linked to vascular disease. Fe-S cluster binding proteins in endothelial and smooth muscle cells contribute to redox signaling and metabolic regulation.
Fe-S cluster defects and iron-related disorders
Disruption of Fe-S cluster biogenesis leads to iron accumulation and oxidative stress, which are hallmarks of several human disorders. In bacteria, zinc toxicity impairs Fe-S cluster biogenesis, suggesting that metal imbalance can compromise Fe-S cluster binding.
Fe-S cluster binding in fungal pathogenesis and drug targeting
Fe-S cluster signaling is central to fungal iron regulation, making it a potential target for antifungal strategies. Understanding how fungi use Fe-S clusters to sense iron could inform new therapeutic approaches.
From iron-sulfur cluster binding-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of FDX2 impair mitochondrial Fe-S cluster assembly? | FDX2 knockout cell line |
| How do point mutations in ISCU affect cluster binding? | ISCU point mutation knock-in |
| Can ATE1 Fe-S cluster binding be reconstituted in vitro? | ATE1 overexpression and purification |
| Does MagR require Fe-S cluster for magnetic sensing? | MagR knock-in with tag |
| How does zinc toxicity affect Fe-S cluster biogenesis? | E. coli knockout of ISC genes |
| What is the feedback regulation of Fe-S cluster biogenesis? | Reporter strains and CRISPR interference |
How to Study the iron-sulfur cluster binding Process
| Method | What It Measures | Typical Application |
|---|---|---|
| UV-visible spectroscopy | Fe-S cluster absorbance | Reconstitution and binding assays |
| EPR spectroscopy | Paramagnetic cluster states | Characterization of Fe-S proteins |
| Magnetic measurements | Magnetic properties of MagR | Fe-S cluster binding effects |
| Gene knockout | Loss-of-function phenotypes | Fe-S cluster biogenesis genes |
| Reporter assays | Iron homeostasis regulation | Bacterial Fe-S cluster regulation |
| Protein purification | Recombinant Fe-S proteins | In vitro reconstitution |
| CRISPR screening | Gene essentiality and function | Fe-S cluster related genes |
Biochemical reconstitution of Fe-S clusters
Reconstitution assays allow direct measurement of Fe-S cluster binding by purified proteins, as demonstrated for ATE1. These methods use iron and sulfide donors under anaerobic conditions and monitor cluster incorporation by spectroscopy.
Genetic and phenotypic analysis in bacteria
E. coli models are powerful for studying Fe-S cluster biogenesis and iron homeostasis, including the effects of zinc toxicity. Knockout and complementation studies reveal the roles of ISC and SUF systems.
Mitochondrial Fe-S cluster assembly assays
Mitochondrial Fe-S cluster assembly can be studied using purified components and cell-based assays, focusing on the core complex and ferredoxin-2. These approaches define the steps of cluster transfer and regulation.
Spectroscopic and magnetic characterization
Fe-S clusters have distinctive spectroscopic signatures, and magnetic properties of proteins like MagR are modulated by cluster binding. Electron paramagnetic resonance and magnetic measurements are used to characterize cluster-bound states.
How CRISPR Can Be Used to Study GO:0051536 iron-sulfur cluster binding
Knockout
CRISPR knockout of Fe-S cluster binding genes such as FDX2 or ISCU allows researchers to assess loss-of-function phenotypes in mitochondrial assembly and cellular iron homeostasis.
Point Mutation
Point mutations in Fe-S cluster binding proteins can be introduced to dissect specific residues required for cluster coordination or protein-protein interactions.
Knock-in
Knock-in of tagged versions of Fe-S proteins, such as MagR, enables localization and interaction studies while preserving endogenous regulation.
Overexpression
Overexpression of Fe-S cluster assembly proteins like ATE1 facilitates biochemical reconstitution and structural studies.
How EDITGENE Supports iron-sulfur cluster binding Research
Researchers studying iron-sulfur cluster binding-related genes often need to determine whether a candidate gene is causally involved in Fe-S cluster assembly, iron homeostasis, or related disease processes. EDITGENE provides comprehensive CRISPR-based services to accelerate this discovery.
Contact EDITGENE today to design your custom CRISPR model for iron-sulfur cluster binding research.
Frequently Asked Questions About iron-sulfur cluster binding
What is GO:0051536 iron-sulfur cluster binding?
GO:0051536 is a Gene Ontology molecular function term defined as binding to an iron-sulfur cluster, a combination of iron and sulfur atoms.
What genes are involved in iron-sulfur cluster binding?
Key genes include NFS1, ISCU, FDX2, ATE1, MagR, and bacterial ISC system genes.
What is the role of mitochondrial Fe-S clusters?
Mitochondrial Fe-S clusters are essential for respiration, metabolism, and iron homeostasis, and their assembly involves the core complex and ferredoxin-2.
How is Fe-S cluster biogenesis regulated?
Fe-S cluster biogenesis is regulated by feedback mechanisms and transcription factors such as IscR in bacteria.
What diseases are linked to Fe-S cluster binding?
Fe-S cluster dysfunction is linked to vascular disease, iron-related disorders, and fungal pathogenesis.
How can I study Fe-S cluster binding in the lab?
Methods include biochemical reconstitution, spectroscopy, gene knockout, and CRISPR screening.
What is the difference between [2Fe-2S] and [4Fe-4S] clusters?
They are different cluster types with distinct iron-sulfur stoichiometries and electronic properties.
Does zinc affect Fe-S cluster biogenesis?
Yes, zinc toxicity impairs Fe-S cluster biogenesis in Escherichia coli.
What is the role of ferredoxin-2 in Fe-S cluster assembly?
Ferredoxin-2 binds to the core assembly complex in a two-stage manner to facilitate cluster formation.
Can CRISPR be used to study Fe-S cluster genes?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression models are widely used.
Conclusion
GO:0051536 iron-sulfur cluster binding represents a fundamental molecular function that underpins diverse biological processes, from mitochondrial respiration to bacterial iron homeostasis. The assembly and regulation of Fe-S clusters involve intricate protein machineries and feedback mechanisms. Dysregulation of Fe-S cluster binding is associated with human disease, making it a compelling target for research and therapeutic intervention. CRISPR-based models and biochemical assays provide powerful tools to dissect these pathways.
References
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- 3. Gupta M et al.. 2020. Iron-sulfur cluster signaling: The common thread in fungal iron regulation.. Curr Opin Chem Biol 55:189-201 PMID: 32234663
- 4. Ding H. 2025. Iron-sulfur cluster biogenesis and regulation of intracellular iron homeostasis in Escherichia coli.. Metallomics 17(12) PMID: 41263481
- 5. Van V et al.. 2023. Reconstitution of the Arginyltransferase (ATE1) Iron-Sulfur Cluster.. Methods Mol Biol 2620:209-217 PMID: 37010764
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- 7. Guo Z et al.. 2021. Modulation of MagR magnetic properties via iron-sulfur cluster binding.. Sci Rep 11(1):23941 PMID: 34907239
- 8. Stuteley SM et al.. 2025. Feedback regulation of iron-sulfur cluster biogenesis.. bioRxiv PMID: 40667192
