GO:0097100 supercoiled DNA binding: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0097100 (supercoiled DNA binding) describes the molecular function of binding to supercoiled DNA, the torsionaly stressed form of DNA that arises during replication and transcription.
• Supercoiled DNA binding is central to genome maintenance because many essential machines, including condensin, Smc5/6, gyrase and Cascade, recognize or generate supercoils.
• Binding can be negatively or positively supercoil selective, as shown for IFI16, which binds both supercoiled and linear DNA through distinct modes.
• Quantitative models and single-molecule assays now allow precise measurement of supercoiling-dependent binding affinities and kinetics.
• Dysregulation of supercoiled DNA binding is linked to cancer, immune sensing and genome instability, making it a target for mechanistic and therapeutic studies.
• CRISPR knockout, point-mutation, knock-in and overexpression models enable causal testing of supercoiled DNA binding proteins in cells and organisms.
Description
Supercoiled DNA binding (GO:0097100) is a molecular function defined as binding to supercoiled DNA, the topologically constrained form of the double helix that is generated when DNA is over- or under-wound during replication and transcription. In cells, template DNA becomes negatively supercoiled in the receding downstream region and positively supercoiled in the approaching downstream region, creating a dynamic landscape of torsional stress that must be recognized and managed by dedicated proteins. This function is therefore not a passive interaction but a selective recognition event that couples DNA topology to genome transactions. Researchers study supercoiled DNA binding because it underlies chromosome organization, DNA replication, transcription regulation and genome stability. Proteins such as condensin, Smc5/6, DNA gyrase and the Cascade complex use supercoil recognition to perform loop extrusion, topological stress relief and target search. The specificity of these interactions can be striking: IFI16 binds supercoiled and linear DNA through dual modes, illustrating how a single protein can decode both topology and structure. Methodological advances, including dual-trap optical tweezers and quantitative binding models, now allow researchers to generate defined supercoiled substrates and measure binding with high precision. This article synthesizes the QuickGO definition and verified literature to provide a research-grade overview of GO:0097100, its mechanisms, key genes, disease relevance and experimental strategies.
supercoiled DNA binding At A Glance
| GO ID | GO:0097100 |
|---|---|
| GO term | supercoiled DNA binding |
| Ontology | molecular_function |
| Synonym | none |
| Major function | Selective binding to negatively or positively supercoiled DNA during replication, transcription and chromosome organization |
| Definition source context | Template DNA is negatively supercoiled in receding downstream DNA and positively supercoiled in approaching downstream DNA |
| Example binders | Cascade, IFI16, condensin, Smc5/6, DNA gyrase |
| Experimental readouts | Supercoiled mini-circles, optical tweezers, quantitative binding models |
| Disease relevance | Cancer, innate immune sensing and genome instability |
What Is GO:0097100?
GO:0097100 (supercoiled DNA binding) is the molecular function of selectively binding to supercoiled DNA, a topologically stressed conformation in which the DNA helix is over-wound (positive supercoiling) or under-wound (negative supercoiling) relative to relaxed B-DNA. The QuickGO definition notes that during replication and transcription, template DNA is negatively supercoiled in the receding downstream DNA and positively supercoiled in the approaching downstream DNA, so proteins with this function must recognize specific supercoil geometries and torsional states. This function is distinct from generic double-stranded DNA binding because it depends on the topological state of the substrate, and it can be quantified using supercoiled mini-circles, single-molecule force spectroscopy and binding models that incorporate supercoiling density.
Why Is supercoiled DNA binding Important in Cell Biology?
Supercoiled DNA binding is important because it converts DNA topology into biological action. During replication and transcription, the template strand is continuously unwound, generating negative supercoils behind the fork and positive supercoils ahead of it. Proteins that bind supercoiled DNA, such as condensin, Smc5/6 and DNA gyrase, use this topology to organize chromosomes, relieve torsional stress and maintain genome stability. In immunity, IFI16 senses supercoiled DNA through a dual binding mode, linking DNA topology to innate immune signaling. Because supercoiling-dependent binding is quantitative and tunable, it is also a powerful experimental handle: researchers can generate defined supercoiled substrates and measure how mutations, drugs or cellular states alter binding. Understanding GO:0097100 therefore informs chromosome biology, transcription regulation, antimicrobial targeting and cancer research.
• Supercoiled DNA binding is required for chromosome organization and loop extrusion by condensin and Smc5/6.
• It enables DNA gyrase to capture DNA crossovers and regulate topological stress during replication.
• Cascade uses supercoiled DNA binding and bending for target search in CRISPR adaptation.
• IFI16 binds supercoiled and linear DNA through distinct modes, connecting topology to innate immunity.
• Quantitative models of supercoiling-dependent binding guide single-molecule and bulk experiments.
• Dual-trap optical tweezers allow controlled generation of negatively supercoiled DNA for binding assays.
• Supercoiled mini-circles provide defined substrates to probe nuclease and binding protein activity.
• Dysregulation of supercoil recognition contributes to genome instability and cancer.
• Supercoiled DNA binding proteins are candidate targets for antibiotics and anticancer strategies.
• CRISPR-based models enable causal testing of supercoiled DNA binding genes in disease contexts.
Molecular Mechanism of supercoiled DNA binding
Recognition of negative supercoils during replication and transcription
In simple terms: When DNA is unwound, the DNA behind the moving machine becomes over-twisted in the opposite direction, and certain proteins recognize this shape.
During replication and transcription, template DNA is negatively supercoiled in the receding downstream DNA and positively supercoiled in the approaching downstream DNA. Proteins with supercoiled DNA binding activity recognize these distinct topological states. For example, Cascade binds and bends negatively supercoiled DNA, a step important for target search during CRISPR adaptation. Human Smc5/6 recognizes transcription-generated positive DNA supercoils, linking transcription to genome maintenance. This recognition is not sequence-specific in the classical sense but depends on the torsional and geometric features of the supercoiled substrate.
Structural basis of supercoil capture by DNA gyrase
In simple terms: Some enzymes grab the crossing point of DNA strands that forms when DNA is supercoiled.
DNA gyrase captures DNA crossovers, a structural feature enriched in supercoiled DNA. The structural basis of DNA crossover capture by Escherichia coli DNA gyrase has been resolved, revealing how the enzyme recognizes and stabilizes the crossover geometry to introduce negative supercoils. This mechanism illustrates how supercoiled DNA binding can be coupled to catalysis, with the bound topology determining the reaction outcome. Such structural insights are essential for understanding how gyrase inhibitors and mutations affect supercoil handling.
Dual-mode binding of IFI16 to supercoiled and linear DNA
In simple terms: One protein can use two different binding modes, one for twisted DNA and one for straight DNA.
IFI16 binds supercoiled and linear DNA through a dual mode, as shown by biochemical characterization. This dual recognition allows IFI16 to sense different DNA states and may contribute to innate immune discrimination between self and foreign DNA. The existence of dual modes highlights that supercoiled DNA binding is not always exclusive; a single protein can combine topology-selective and structure-selective interactions.
Condensin-driven loop extrusion on supercoiled DNA
In simple terms: Ring-shaped protein machines pull DNA into loops, and they work differently when the DNA is twisted.
Condensin drives loop extrusion on supercoiled DNA, a process central to chromosome compaction. Single-molecule studies show that supercoiling modulates condensin activity, and condensin can in turn alter DNA topology. This reciprocal relationship means that supercoiled DNA binding by condensin is both a sensor and an effector of chromosome architecture. Smc5/6 similarly recognizes positive supercoils generated by transcription, providing a second example of SMC complexes reading topological signals.
Quantitative modeling and single-molecule measurement
In simple terms: Scientists can calculate and measure how strongly proteins stick to twisted DNA.
Supercoiling-dependent DNA binding can be described by quantitative models that relate binding affinity to supercoil density, and these models have been applied to both bulk and single-molecule experiments. Dual-trap optical tweezers enable the generation of negatively supercoiled DNA with controlled tension, allowing direct measurement of binding kinetics. Hyper-negatively supercoiled mini-circles provide complementary substrates for probing nuclease and DNA binding protein activities. Together, these approaches allow researchers to dissect the thermodynamics and mechanics of GO:0097100 in vitro.
Key Genes Involved in GO:0097100 supercoiled DNA binding
The following genes and protein complexes represent major experimental models for studying supercoiled DNA binding (GO:0097100), based on verified literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| Cascade (CRISPR adaptation complex) | Binds and bends negatively supercoiled DNA during target search | Model for topology-selective target recognition in CRISPR adaptation |
| IFI16 | Dual-mode binding to supercoiled and linear DNA | Links DNA topology to innate immune sensing |
| Condensin | Drives loop extrusion on supercoiled DNA | Central to chromosome compaction and architecture |
| Smc5/6 | Recognizes transcription-generated positive DNA supercoils | Connects transcription to genome maintenance |
| DNA gyrase (GyrA/GyrB) | Captures DNA crossovers and introduces negative supercoils | Antibacterial target and model for crossover recognition |
| Topoisomerase I | Relieves torsional stress during replication and transcription | Context for supercoil generation and binding |
| Topoisomerase II | Manages positive supercoils ahead of replication forks | Relevant to genome stability and drug targeting |
| RNA polymerase | Generates positive and negative supercoils during transcription | Source of topological signals recognized by Smc5/6 |
| Replication machinery (e.g., helicase) | Creates negative supercoils behind the fork | Provides substrate for supercoiled DNA binding proteins |
| SMC complex subunits | Bind and organize supercoiled DNA | Core chromosome organization factors |
| Nucleases (e.g., S1, DNase I) | Probe supercoiled mini-circles | Used to validate supercoiled substrates in vitro |
| Single-molecule DNA binding proteins | Measured for supercoiling-dependent affinity | Benchmark for quantitative binding models |
| Gyrase inhibitors (e.g., fluoroquinolones) | Target DNA gyrase crossover capture | Antibiotic development and resistance studies |
| IFI16 mutants | Alter dual-mode binding | Probe immune signaling specificity |
| Condensin mutants | Alter loop extrusion on supercoiled DNA | Test chromosome compaction mechanisms |
| Smc5/6 mutants | Alter positive supercoil recognition | Test transcription-genome stability coupling |
| Cascade mutants | Alter supercoiled DNA bending | Study CRISPR adaptation target search |
How Is supercoiled DNA binding Regulated?
Supercoiled DNA binding is regulated by the cellular topological state, which is set by the balance of DNA unwinding during replication and transcription and by topoisomerase and gyrase activities. Transcription generates positive supercoils ahead of RNA polymerase and negative supercoils behind it, and Smc5/6 specifically recognizes the positive supercoils, providing a transcription-dependent regulatory input. DNA gyrase introduces negative supercoils and captures crossovers, so its expression and activity directly modulate the availability of supercoiled substrates. In addition, post-translational modifications and protein-protein interactions can alter the affinity of binders such as IFI16 and condensin for supercoiled DNA, though the precise regulatory circuits remain an active area of study. Quantitative models predict that small changes in supercoil density can shift binding occupancy, making topology itself a regulatory parameter.
supercoiled DNA binding and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| Smc5/6 | Genome instability, transcription-associated stress | Knockout and point-mutation cell lines |
| Condensin | Chromosomal instability, developmental disorders | Knock-in of patient variants and loop extrusion assays |
| IFI16 | Autoimmune and inflammatory signaling | Overexpression and binding-mode mutants |
| DNA gyrase (bacterial) | Antibiotic resistance | Bacterial knockout and inhibitor assays |
| Cascade | CRISPR adaptation and phage resistance | Mutant Cascade complexes and supercoiled DNA binding assays |
Supercoiled DNA binding and cancer
Altered supercoil recognition contributes to genome instability, a hallmark of cancer. Smc5/6 recognizes transcription-generated positive supercoils, and defects in this recognition can impair genome maintenance. Condensin-driven loop extrusion on supercoiled DNA is essential for chromosome compaction, and its dysregulation is associated with chromosomal instability. DNA gyrase, though bacterial, serves as a paradigm for crossover capture, and its structural mechanism informs the design of anticancer topoisomerase inhibitors. Together, these findings link GO:0097100 to cancer biology through chromosome organization and topological stress management.
Supercoiled DNA binding in innate immunity
IFI16 binds supercoiled and linear DNA through dual modes, and this recognition is relevant to innate immune sensing of DNA. Because supercoiled DNA is a common intermediate during replication and transcription, the ability of IFI16 to distinguish topological states may help avoid inappropriate immune activation while still detecting foreign DNA. Dysregulated IFI16 binding has been implicated in autoimmune and inflammatory conditions, making supercoiled DNA binding a potential node for therapeutic intervention.
Supercoiled DNA binding and genome stability disorders
Proteins that bind supercoiled DNA, including condensin and Smc5/6, are central to chromosome segregation and DNA repair. Mutations that impair their supercoil recognition can lead to genome instability, developmental defects and sensitivity to replication stress. Studying these proteins with CRISPR models can reveal how specific binding interfaces contribute to disease phenotypes.
From supercoiled DNA binding-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of a supercoiled DNA binding protein cause genome instability? | CRISPR knockout cell line |
| Does a disease-associated point mutation alter supercoil selectivity? | Point-mutation knock-in cell line |
| Can a tagged protein be used to map supercoiled DNA binding sites? | Tagged knock-in (e.g., GFP or epitope tag) |
| Does overexpression of a supercoiled DNA binder drive immune signaling? | Overexpression cell line |
| Which domains are required for crossover capture? | Domain-deletion knock-in or point mutants |
| Can supercoiled DNA binding be measured in live cells? | Single-molecule imaging in knockout or knock-in backgrounds |
How to Study the supercoiled DNA binding Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Supercoiled mini-circle assay | Binding and nuclease sensitivity of supercoiled DNA | In vitro validation of topology-selective binders |
| Dual-trap optical tweezers | Force and extension of supercoiled DNA with bound proteins | Single-molecule binding kinetics |
| Quantitative binding model | Predicted affinity as a function of supercoil density | Data fitting for bulk and single-molecule experiments |
| Cryo-EM / crystallography | Structural basis of crossover capture | Mechanistic studies of gyrase and related enzymes |
| Electrophoretic mobility shift assay | Binding to supercoiled versus relaxed DNA | Rapid screening of mutants |
| Atomic force microscopy | DNA bending and looping by bound proteins | Visualizing supercoil-induced conformational changes |
| Chromatin immunoprecipitation | Genomic localization of supercoiled DNA binders | Mapping transcription-generated supercoil recognition |
| Live-cell imaging | Dynamic recruitment to supercoiled DNA regions | Testing knockout or knock-in effects in cells |
Supercoiled mini-circle assays
Hyper-negatively supercoiled mini-circles can be probed with nucleases and DNA binding proteins to assess topology-selective binding. This method provides defined substrates and is compatible with gel electrophoresis and footprinting.
Dual-trap optical tweezers
Dual-trap optical tweezers generate negatively supercoiled DNA under controlled tension, enabling real-time measurement of binding kinetics and mechanics. This approach is ideal for studying how tension and supercoil density affect binding.
Quantitative binding modeling
Supercoiling-dependent DNA binding can be modeled quantitatively and applied to both bulk and single-molecule experiments. These models help interpret binding affinities and predict occupancy under cellular supercoil densities.
Structural biology and crosslinking
Structural studies of DNA gyrase capturing crossovers reveal the molecular basis of supercoil recognition. Complementary crosslinking and biochemical assays can map interfaces in other supercoiled DNA binding proteins.
How CRISPR Can Be Used to Study GO:0097100 supercoiled DNA binding
Knockout
CRISPR knockout of genes encoding supercoiled DNA binding proteins, such as Smc5/6 or condensin subunits, allows researchers to test loss-of-function phenotypes including genome instability and impaired loop extrusion. Knockout cell lines can be combined with supercoiled DNA binding assays to determine whether the phenotype is due to loss of topology recognition.
Point Mutation
Point mutations can be introduced into supercoiled DNA binding domains to dissect residues required for crossover capture or supercoil selectivity. For example, mutations in IFI16 that alter dual-mode binding can be tested for effects on immune signaling. Point-mutation models are essential for linking specific binding interfaces to disease phenotypes.
Knock-in
Knock-in of tagged or patient-derived variants enables tracking of supercoiled DNA binding proteins in their native context. Tagged knock-in lines can be used for chromatin immunoprecipitation and live-cell imaging to map binding sites and dynamics. This approach preserves endogenous regulation and is ideal for studying disease-associated mutations.
Overexpression
Overexpression of supercoiled DNA binding proteins, such as IFI16, can reveal gain-of-function effects on innate immune signaling and DNA damage responses. Overexpression models are useful for biochemical purification and for testing whether increased binding capacity alters cellular topology.
How EDITGENE Supports supercoiled DNA binding Research
Researchers studying supercoiled DNA binding-related genes often need to determine whether a candidate gene is causally involved in a specific phenotype, such as genome instability, immune signaling or chromosome organization. Establishing causality requires precise genetic models that isolate the function of the gene of interest without confounding background effects. EDITGENE provides end-to-end CRISPR services to generate such models, from knockout and point-mutation cell lines to knock-in reporters and overexpression systems, supported by library screening and bioinformatics.
Contact EDITGENE today to design your custom CRISPR model for supercoiled DNA binding research.
Frequently Asked Questions About supercoiled DNA binding
What is supercoiled DNA binding?
Supercoiled DNA binding (GO:0097100) is the molecular function of selectively binding to supercoiled DNA, the over- or under-wound form of DNA generated during replication and transcription.
What genes are involved in supercoiled DNA binding?
Key genes and complexes include Cascade, IFI16, condensin, Smc5/6 and DNA gyrase, all of which recognize or process supercoiled DNA.
What is the GO ID for supercoiled DNA binding?
The Gene Ontology ID is GO:0097100, with the official name supercoiled DNA binding and ontology aspect molecular_function.
Why is supercoiled DNA binding important?
It links DNA topology to chromosome organization, replication, transcription and genome stability, and its dysregulation is associated with cancer and immune disorders.
How is supercoiled DNA binding measured?
Common methods include supercoiled mini-circle assays, dual-trap optical tweezers and quantitative binding models.
What is the difference between supercoiled and linear DNA binding?
Supercoiled DNA binding depends on the torsional state of the DNA, whereas linear DNA binding does not; some proteins such as IFI16 can bind both through distinct modes.
Which proteins recognize positive supercoils?
Human Smc5/6 recognizes transcription-generated positive DNA supercoils, and DNA gyrase captures crossovers associated with supercoiled DNA.
Can CRISPR be used to study supercoiled DNA binding?
Yes, CRISPR knockout, point-mutation, knock-in and overexpression models allow causal testing of supercoiled DNA binding genes in cells.
What diseases are linked to supercoiled DNA binding?
Genome instability, cancer and innate immune disorders have been linked to proteins that bind or process supercoiled DNA.
How do I choose a model for supercoiled DNA binding research?
The choice depends on the question: knockout for loss-of-function, point mutation for residue-level dissection, knock-in for endogenous tracking and overexpression for gain-of-function studies.
Conclusion
Supercoiled DNA binding (GO:0097100) is a fundamental molecular function that allows cells to sense and act on the torsional state of DNA during replication, transcription and chromosome organization. Proteins such as Cascade, IFI16, condensin, Smc5/6 and DNA gyrase illustrate the diversity of mechanisms by which supercoiled DNA is recognized, bent, captured or extruded. Advances in single-molecule tools and quantitative models now make it possible to measure supercoiling-dependent binding with high precision. CRISPR-based models provide the causal framework needed to link these molecular events to disease phenotypes, offering a clear path for therapeutic discovery.
References
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- 3. Saintomé C et al.. 2018. Probing hyper-negatively supercoiled mini-circles with nucleases and DNA binding proteins.. PLoS One 13(8):e0202138 PMID: 30114256
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- 5. Diman A et al.. 2024. Human Smc5/6 recognises transcription-generated positive DNA supercoils.. Nat Commun 15(1):7805 PMID: 39242537
- 6. King GA et al.. 2022. Generating Negatively Supercoiled DNA Using Dual-Trap Optical Tweezers.. Methods Mol Biol 2478:243-272 PMID: 36063323
- 7. Kolbeck PJ et al.. 2024. Supercoiling-dependent DNA binding: quantitative modeling and applications to bulk and single-molecule experiments.. Nucleic Acids Res 52(1):59-72 PMID: 38000393
- 8. Vayssières M et al.. 2024. Structural basis of DNA crossover capture by Escherichia coli DNA gyrase.. Science 384(6692):227-232 PMID: 38603484
