Recombinant Escherichia coli O139:H28 ATP synthase subunit a (atpB)

How does atpB contribute to ATP synthase function?

The atpB subunit plays a critical role in the ATP synthase complex's function by forming part of the proton channel in the membrane-embedded Fo domain. It works in concert with other subunits to facilitate proton translocation across the membrane, which drives the rotary mechanism of ATP synthesis.

The subunit a (atpB) provides a physical link between the proton channel and the peripheral stalk of the ATP synthase complex. This linkage is essential for coupling proton movement to the rotary mechanics of the enzyme. In the assembled complex, atpB interacts with the c-ring, allowing protons to flow through the membrane while generating rotational torque that is transmitted to the catalytic F1 domain, ultimately driving ATP synthesis .

How is atpB integrated into the ATP synthase complex assembly?

ATP synthase assembly is a sophisticated process involving multiple modules. Current evidence suggests that the assembly pathway for ATP synthase involves separate assembly of the F1 sector, the c-ring, and the peripheral stalk components. The mitochondrial-encoded subunits, including subunit a (atpB), are typically added at later stages of assembly.

The assembly sequence proposed for mammalian ATP synthase suggests that:

• The c-ring forms first

• The F1 domain binds to the c-ring

• The stator arm components attach

• Finally, subunits a and A6L are incorporated

Research indicates that ATP synthase can form a complex of approximately 550 kDa even in the absence of subunits a and A6L, suggesting these components are added in the final stages of assembly. This staged assembly process allows for balanced production of nuclear and mitochondrially encoded components .

What are the optimal conditions for expressing recombinant E. coli O139:H28 atpB protein?

For optimal expression of recombinant E. coli O139:H28 atpB protein, researchers should consider several methodological factors:

• Expression System: The full-length atpB protein (1-271 amino acids) can be successfully expressed in E. coli expression systems with N-terminal His tags to facilitate purification .

• Induction Conditions: While specific induction conditions for E. coli O139:H28 atpB aren't detailed in the provided resources, lessons from similar ATP synthase subunit expressions suggest carefully optimized induction temperatures and inducer concentrations are critical. For instance, in the case of chloroplast ATP synthase β-subunit, high-level expression was achieved, constituting 50-70% of total cell protein under appropriate induction conditions .

• Inclusion Body Formation: Researchers should anticipate that overexpressed atpB protein may form inclusion bodies, which is common with membrane proteins. This necessitates appropriate solubilization and refolding strategies to obtain functional protein .

• Protein Extraction: Given that atpB is a membrane protein, specialized extraction methods using appropriate detergents may be necessary to maintain protein integrity during purification.

A methodological approach similar to that used for chloroplast ATP synthase β-subunit could be adapted, where inclusion bodies were solubilized with 4 M urea followed by stepwise dialysis to remove the urea, resulting in over 50% recovery of functional protein .

What purification strategies yield the highest purity atpB protein?

For high-purity recombinant E. coli O139:H28 atpB protein, the following purification methodology is recommended:

• Initial Purification: Exploit the N-terminal His tag by using immobilized metal affinity chromatography (IMAC) as the primary purification step .

• Secondary Purification: Following IMAC, additional chromatographic steps such as ion exchange or size exclusion chromatography may further enhance purity.

• Quality Assessment: Verify protein purity using SDS-PAGE analysis. Commercial preparations typically achieve greater than 90% purity as determined by SDS-PAGE .

• Functional Validation: Assess the functionality of the purified protein through activity assays or binding studies, similar to how the refolded chloroplast ATP synthase β-subunit was validated for nucleotide binding properties .

The purified protein can be stored as a lyophilized powder, which helps maintain stability during long-term storage. For working solutions, reconstitution in an appropriate buffer (typically Tris/PBS-based buffer with 6% Trehalose, pH 8.0) is recommended .

How can researchers optimize the refolding of atpB protein from inclusion bodies?

When atpB forms inclusion bodies during overexpression, researchers can implement the following methodological approach to optimize refolding:

• Solubilization Protocol: Solubilize inclusion bodies containing atpB protein using denaturing agents. Based on successful approaches with similar ATP synthase subunits, 4 M urea has been effective .

• Controlled Refolding: Implement a stepwise dialysis protocol to gradually remove the denaturing agent, allowing the protein to adopt its native conformation. This approach has demonstrated success in recovering more than 50% of functional protein in similar ATP synthase subunits .

• Refolding Buffer Optimization: Include appropriate additives in the refolding buffer such as glycerol, reduced and oxidized glutathione, or low concentrations of detergents to prevent aggregation during the refolding process.

• Functional Verification: Verify that the refolded protein exhibits appropriate binding or enzymatic properties. For example, with the ATP synthase β-subunit, researchers confirmed that the refolded protein demonstrated specific and selective nucleotide binding properties identical to those of the native protein .

• Storage Considerations: After successful refolding, add cryoprotectants such as glycerol (typically 5-50% final concentration) and aliquot for long-term storage at -20°C/-80°C to maintain protein stability and prevent repeated freeze-thaw cycles .

How should researchers design experiments to study atpB phosphorylation states?

When designing experiments to investigate atpB phosphorylation states, researchers should consider the following methodological framework:

• Mutational Analysis Approach: Generate specific mutations at potential phosphorylation sites, such as serine residues. For instance, studies of ATP synthase β-subunit have employed alanine substitutions (preventing phosphorylation) and aspartic acid substitutions (phosphomimetic) to assess the functional impact of phosphorylation at specific sites .

• Confirmation of Mutations: Validate the presence of desired mutations through PCR amplification and Sanger sequencing. For organisms with multiple genome copies (like plastids), confirm homoplasmy through techniques such as Southern blotting to ensure complete transformation .

• Transcript Analysis: Assess whether mutations affect transcript abundance using Northern blot analysis or qPCR to distinguish between effects on protein function versus expression levels .

• Functional Analysis: Measure the impact of phosphorylation site mutations on ATP synthase function through:

  • Growth analysis (for in vivo studies)

  • ATP synthesis assays (for in vitro studies)

  • Proton motive force (pmf) measurements

  • Analysis of complex assembly via native gel electrophoresis

• Comparative Analysis: Implement a systematic comparison between wild-type, phospho-null (e.g., S→A), and phosphomimetic (e.g., S→D) mutations to comprehensively assess the role of phosphorylation .

This experimental design approach can reveal whether N-terminal phosphorylation of ATP synthase subunits affects complex assembly, stability, or activity. Evidence suggests that phosphorylation states may influence proper ATP synthase accumulation during complex assembly .

What controls are essential when studying atpB function in reconstituted systems?

When investigating atpB function in reconstituted systems, researchers must implement the following essential controls:

• Protein Quality Controls:

  • Purity assessment via SDS-PAGE (>90% purity is recommended)

  • Western blot verification of identity and integrity

  • Circular dichroism to confirm proper secondary structure

  • Limited proteolysis to assess proper folding

• Functional Controls:

  • ATP synthase activity in the absence of atpB to establish baseline

  • Comparison with native membrane-derived ATP synthase

  • Proton permeability measurements in liposomes with and without reconstituted atpB

  • Inhibitor studies with known ATP synthase inhibitors (e.g., oligomycin)

• System Integrity Controls:

  • Liposome integrity checks before and after reconstitution

  • Protein orientation assays to confirm proper insertion direction

  • Lipid composition controls to match physiological conditions

• Experimental Design Controls:

  • Use of single-case experimental design approaches such as reversal design (A-B-A) to demonstrate causality between atpB incorporation and observed effects

  • Multiple baseline measurements to establish stability before manipulation

  • Systematic variation of conditions to identify critical parameters

These methodological controls ensure that observed effects can be specifically attributed to atpB function rather than experimental artifacts or contaminating factors.

How can researchers effectively study atpB interactions with other ATP synthase subunits?

To effectively investigate atpB interactions with other ATP synthase subunits, researchers should employ the following methodological approaches:

• Crosslinking Studies:

  • Implement chemical crosslinking with defined spacer lengths to identify proximity relationships

  • Use photo-crosslinking with site-specific incorporation of photo-reactive amino acids to map interaction sites

  • Analyze crosslinked products by mass spectrometry to identify interaction interfaces

• Co-immunoprecipitation Experiments:

  • Utilize antibodies against atpB or tagged versions of atpB to pull down interacting partners

  • Perform reciprocal co-immunoprecipitations with antibodies against suspected interacting subunits

  • Analyze co-precipitated proteins by Western blot or mass spectrometry

• Fluorescence Resonance Energy Transfer (FRET):

  • Generate fluorescently labeled subunits to measure proximity in reconstituted systems

  • Employ acceptor photobleaching or fluorescence lifetime measurements to quantify FRET efficiency

  • Map interaction surfaces through site-directed labeling strategies

• Mutagenesis Approaches:

  • Create a library of point mutations in atpB

  • Assess the impact of mutations on complex assembly and interactions

  • Identify critical residues that disrupt specific subunit interactions

• Native Complex Analysis:

  • Employ clear native polyacrylamide gel electrophoresis (CN-PAGE) or blue native PAGE (BN-PAGE) to analyze intact complexes

  • Compare complex formation with wild-type versus mutated atpB

  • Analyze subcomplexes that form in the absence of specific interactions

These approaches can provide insights into how atpB interacts with other subunits, particularly its role in stabilizing holocomplex V and its interactions with the c-ring and peripheral stalk components of ATP synthase .

What strategies can address poor solubility of recombinant atpB protein?

Addressing poor solubility of recombinant atpB protein requires a multifaceted approach:

• Expression Conditions Optimization:

  • Reduce induction temperature (e.g., 18-25°C instead of 37°C)

  • Decrease inducer concentration to slow protein production

  • Use specialized E. coli strains designed for membrane protein expression

  • Consider co-expression with chaperone proteins

• Fusion Tags Selection:

  • While His-tags are valuable for purification, consider solubility-enhancing fusion partners such as MBP, SUMO, or Thioredoxin

  • Position tags strategically to avoid interfering with membrane insertion

  • Include precision protease cleavage sites for tag removal

• Membrane Protein-Specific Approaches:

  • Express as a fusion with a well-characterized membrane protein

  • Include native lipids in extraction buffers

  • Add specific phospholipids during protein extraction

• Inclusion Body Recovery:

  • If expression still results in inclusion bodies, implement stepwise refolding protocols

  • Use mild solubilization with 4-8 M urea rather than harsh denaturants

  • Employ gradual dialysis for controlled refolding

  • This approach has shown success with ATP synthase subunits, recovering >50% functional protein

• Detergent Screening:

  • Systematically test multiple detergents (DDM, LDAO, Triton X-100, etc.)

  • Evaluate detergent concentration effects

  • Consider detergent mixtures or novel amphipathic agents like SMALPs

• Storage Buffer Optimization:

  • Once solubilized, maintain protein stability with optimized buffers

  • Include stabilizing agents like glycerol (5-50%) and trehalose (6%)

  • Store in multiple small aliquots to avoid repeated freeze-thaw cycles

How can researchers distinguish between functional and non-functional forms of atpB?

Distinguishing between functional and non-functional forms of atpB requires several complementary analytical approaches:

• Structural Analysis:

  • Circular dichroism spectroscopy to assess secondary structure elements

  • Intrinsic fluorescence measurements to evaluate tertiary structure

  • Limited proteolysis to identify properly folded domains versus misfolded regions

  • Size exclusion chromatography to detect aggregation or oligomerization states

• Binding Assays:

  • Assess interaction with known binding partners (e.g., other ATP synthase subunits)

  • Measure nucleotide binding if applicable

  • Evaluate interaction with specific inhibitors

• Functional Reconstitution:

  • Incorporation into liposomes or nanodiscs

  • Measurement of proton translocation activity

  • Assessment of contribution to ATP synthesis when combined with other subunits

  • Evaluation of complex formation by native gel electrophoresis

• In vivo Complementation:

  • Test whether the purified protein can rescue defects in atpB-deficient systems

  • Assess growth phenotypes or ATP synthesis capacity

  • Compare effects with known functional and non-functional control variants

• Thermal Stability Assessment:

  • Differential scanning fluorimetry to measure protein stability

  • Comparison with native protein thermal denaturation profiles

  • Evaluation of stabilizing buffer conditions

These methodologies can collectively provide a comprehensive assessment of whether the recombinant atpB protein has attained its functional conformation, similar to approaches used for other ATP synthase subunits where specific and selective properties identical to the native protein were verified .

What approaches can resolve contradictory results in atpB mutation studies?

When faced with contradictory results in atpB mutation studies, researchers should implement the following methodological approaches to resolve discrepancies:

• Systematic Experimental Design Review:

  • Implement single-case experimental designs like reversal design (A-B-A) for clear establishment of causality

  • Ensure adequate baseline measurements before implementing experimental manipulations

  • Consider multiple-baseline designs to strengthen internal validity

• Genetic Background Verification:

  • Confirm the homoplasmic state of mutations in organisms with multiple genome copies

  • Verify absence of secondary mutations through whole genome sequencing

  • Assess whether contradictory results stem from differences in strain backgrounds

  • Use Southern blot analysis to confirm genomic integration of desired mutations

• Expression Level Analysis:

  • Quantify transcript levels through Northern blot analysis or qPCR to rule out expression differences as the source of contradictory results

  • Measure protein abundance through Western blotting

  • Distinguish between effects on protein function versus abundance

• Phenotypic Characterization Depth:

  • Assess multiple phenotypic outputs (growth, ATP synthesis, complex assembly)

  • Quantify phenotypes under various environmental conditions

  • Consider combinatorial mutations to reveal compensatory mechanisms

  • Compare specific mutations (e.g., S8A, S13A, S13D) to identify site-specific effects

• Statistical Rigor Enhancement:

  • Employ appropriate statistical analysis with adequate sample sizes

  • Consider mixed-effects models to account for variability

  • Calculate effect sizes rather than relying solely on statistical significance

  • Report confidence intervals to better characterize uncertainty

• Methodological Standardization:

  • Compare methodologies between contradictory studies

  • Standardize key protocols across research groups

  • Implement blinded analysis where appropriate

  • Consider interlaboratory validation studies

This structured approach can help researchers systematically identify sources of contradictory results and develop a more coherent understanding of atpB function and the effects of specific mutations.

How should researchers interpret changes in ATP synthase activity following atpB modification?

When interpreting changes in ATP synthase activity following atpB modification, researchers should apply the following analytical framework:

• Distinguish Direct from Indirect Effects:

  • Determine whether activity changes result directly from altered catalytic properties or indirectly from impacts on complex assembly

  • Assess the relationship between ATP synthesis rates and ATP synthase complex abundance

  • Quantify the proportion of fully assembled complexes versus subcomplexes

• Consider Structural Consequences:

  • Analyze how modifications affect interactions with other subunits, particularly the c-ring and peripheral stalk

  • Evaluate impacts on proton channel formation and function

  • Assess potential alterations in the physical link between the proton channel and other subunits

• Evaluate Bioenergetic Parameters:

  • Measure proton motive force (pmf) to determine if reduced activity stems from impaired proton translocation

  • Assess the relationship between electron transfer and ATP synthesis

  • Consider whether modifications alter regulatory feedback between ATP synthase activity and electron transfer

• Analyze Phosphorylation-Specific Effects:

  • Compare the effects of phospho-null (S→A) versus phosphomimetic (S→D) mutations

  • Determine whether phosphorylation affects assembly, stability, or activity

  • Consider site-specific effects (e.g., S8 versus S13 phosphorylation)

• Apply Appropriate Statistical Analysis:

  • Use statistical methods suitable for the experimental design

  • For single-case designs, analyze patterns across phases through visual inspection and statistical testing

  • Report effect sizes and confidence intervals rather than just p-values

• Consider Physiological Context:

  • Evaluate whether in vitro activity changes translate to physiological impacts

  • Assess growth phenotypes or other whole-organism effects

  • Determine whether compensatory mechanisms mitigate the effects of modifications in vivo

This systematic interpretive approach can help researchers distinguish between different mechanisms by which atpB modifications affect ATP synthase function and place findings in appropriate physiological context.

What analytical methods best quantify atpB contribution to ATP synthase assembly?

To optimally quantify atpB's contribution to ATP synthase assembly, researchers should employ the following analytical methodology:

• Native Gel Electrophoresis Techniques:

  • Blue Native PAGE (BN-PAGE) to separate intact ATP synthase complexes and subcomplexes

  • Clear Native PAGE (CN-PAGE) as a milder alternative that preserves more labile interactions

  • Two-dimensional gel electrophoresis (BN-PAGE followed by SDS-PAGE) to identify subunit composition of different complexes and subcomplexes

• Quantitative Mass Spectrometry:

  • SILAC (Stable Isotope Labeling with Amino acids in Cell culture) to quantify changes in complex composition

  • Cross-linking mass spectrometry to map interaction interfaces

  • Targeted proteomics approaches to quantify stoichiometry of complex components

• Imaging Techniques:

  • Cryo-electron microscopy to visualize ATP synthase structure with and without atpB

  • Single-particle analysis to assess structural heterogeneity

  • Tomography to visualize ATP synthase dimers and oligomers in membrane contexts

• Biochemical Fractionation:

  • Sucrose gradient centrifugation to separate assembly intermediates

  • Size exclusion chromatography to quantify complex size distribution

  • Comparison of ATP synthase assembly in the presence of wild-type versus mutant atpB

• Time-Resolved Assembly Analysis:

  • Pulse-chase experiments to track assembly kinetics

  • Inducible expression systems to monitor assembly progression

  • Temperature-sensitive mutants to create synchronous assembly conditions

Research has shown that ATP synthase can assemble into a complex of approximately 550 kDa even in the absence of subunits a (atpB) and A6L, suggesting these components are added at later stages of assembly. Proper quantification can determine whether atpB primarily contributes to complex stability or is essential for initial assembly steps .

How can researchers accurately determine the stoichiometry of atpB in ATP synthase complexes?

Determining the precise stoichiometry of atpB in ATP synthase complexes requires a combination of complementary analytical approaches:

• Quantitative Proteomics:

  • Selected Reaction Monitoring (SRM) or Multiple Reaction Monitoring (MRM) mass spectrometry

  • Use of heavy isotope-labeled peptide standards from each subunit for absolute quantification

  • SILAC-based approaches to determine relative abundance of subunits

  • Data-independent acquisition methods for comprehensive protein quantification

• Radiolabeling Techniques:

  • Incorporation of radioactive amino acids during synthesis

  • Phosphorimaging to quantify labeled subunits

  • Comparison of signal intensities between different subunits with correction for labeling efficiency

• Fluorescence-Based Methods:

  • Site-specific labeling of subunits with fluorescent probes

  • Fluorescence correlation spectroscopy to determine absolute concentrations

  • Single-molecule photobleaching step analysis to count subunits in individual complexes

• Structural Approaches:

  • X-ray crystallography or cryo-EM to determine structural stoichiometry

  • Mass measurement of intact complexes by native mass spectrometry

  • Scanning transmission electron microscopy (STEM) mass mapping

• Genetic Approaches:

  • Titration of expression levels to determine minimal functional stoichiometry

  • Tagged variant co-expression to assess incorporation efficiency

  • Competition experiments between wild-type and mutant forms

• Analytical Ultracentrifugation:

  • Sedimentation velocity experiments to determine complex size

  • Calculation of molecular mass from sedimentation and diffusion coefficients

  • Comparison with theoretical mass based on assumed stoichiometry

These methodologies, when used in combination, can provide robust determination of atpB stoichiometry within ATP synthase complexes and clarify its structural arrangement relative to other subunits, particularly in the context of the proton channel and its interaction with the c-ring and peripheral stalk components .

What are the most promising approaches for studying atpB post-translational modifications?

The study of atpB post-translational modifications represents an emerging research frontier with several promising methodological approaches:

• Mass Spectrometry-Based Approaches:

  • Enrichment strategies for phosphorylated, acetylated, or otherwise modified peptides

  • Top-down proteomics to analyze intact proteins with their modifications

  • Targeted quantitative proteomics to monitor site-specific modification occupancy

  • Cross-linking mass spectrometry to determine how modifications affect interaction interfaces

• Site-Specific Modification Analysis:

  • Generation of phospho-null (S→A) and phosphomimetic (S→D) mutations to assess functional impacts

  • Comparison of single versus combined mutations (e.g., S8A+S13D) to evaluate site interdependence

  • Correlation of modification patterns with physiological conditions

• Structural Biology Integration:

  • Cryo-EM analysis of ATP synthase with native modifications versus mutants

  • Hydrogen-deuterium exchange mass spectrometry to assess conformational impacts of modifications

  • Molecular dynamics simulations to predict modification effects on protein dynamics

• Temporal Dynamics Investigation:

  • Pulse-chase approaches to determine modification kinetics

  • Analysis of modification changes during stress responses

  • Correlation with ATP synthase assembly or degradation kinetics

• Systems Biology Frameworks:

  • Integration of modification data with transcriptomics and metabolomics

  • Network analysis to identify kinases and phosphatases regulating atpB

  • Modeling approaches to predict functional consequences of modification patterns

Evidence suggests that N-terminal phosphorylation of ATP synthase subunits may play a role in proper complex assembly. For instance, mutations at phosphorylation sites S8 and S13 in the β-subunit have demonstrated differential effects on growth, with the S13D phosphomimetic mutation showing the most significant growth impairment . These observations suggest that post-translational modifications may serve as regulatory mechanisms for ATP synthase function and assembly.

What novel technological approaches could advance atpB research?

Several emerging technological approaches hold promise for advancing atpB research:

• Cryo-Electron Tomography:

  • Visualization of ATP synthase in native membrane environments

  • Analysis of supramolecular organization and oligomerization states

  • Integration with subtomogram averaging for high-resolution structural insights

  • Investigation of atpB's role in dimer and oligomer formation

• Single-Molecule Biophysics:

  • Direct observation of proton translocation through atpB-containing channels

  • Real-time monitoring of conformational changes during ATP synthesis

  • Force measurements to determine mechanical coupling between proton flow and rotary motion

  • Correlative fluorescence and force spectroscopy to link structure and function

• Genome Editing Technologies:

  • CRISPR-Cas9 approaches for precise genomic modification of atpB

  • Base editing for introduction of specific mutations without double-strand breaks

  • Prime editing for flexible precision modifications

  • High-throughput mutational scanning of atpB to comprehensively map structure-function relationships

• Synthetic Biology Approaches:

  • Minimal ATP synthase construction to define essential components

  • Integration of non-natural amino acids to probe specific interactions

  • Design of switchable ATP synthases responsive to external stimuli

  • Creation of hybrid systems incorporating features from different species

• Computational Methods:

  • Molecular dynamics simulations of proton translocation through atpB

  • Quantum mechanics/molecular mechanics approaches to model proton transfer energetics

  • Machine learning integration with experimental data to predict optimal mutations

  • Systems biology modeling of ATP synthase in cellular energy dynamics

• Microfluidic Platforms:

  • High-throughput screening of conditions affecting atpB function

  • Single-cell analysis of ATP synthase activity with mutant atpB variants

  • Artificial membrane systems for reconstitution and functional studies

  • Gradient generation for studying ATP synthase under varying pmf conditions

These technological innovations could provide unprecedented insights into atpB's structure, function, and integration within the ATP synthase complex, potentially leading to new applications in bioenergetics and synthetic biology.

How might research on atpB contribute to understanding ATP synthase evolution?

Research on atpB can provide significant insights into ATP synthase evolution through the following methodological approaches:

• Comparative Genomics and Phylogenetics:

  • Analysis of atpB sequence conservation across bacterial, archaeal, and eukaryotic domains

  • Identification of domain-specific features versus universally conserved elements

  • Reconstruction of ancestral sequences to understand evolutionary trajectories

  • Correlation of sequence changes with structural and functional innovations

• Structure-Function Relationship Mapping:

  • Comparison of atpB's role in proton translocation across diverse species

  • Analysis of co-evolution between atpB and interacting subunits

  • Identification of species-specific adaptations versus core functional elements

  • Investigation of how atpB contributes to ATP synthase dimer and oligomer formation in different organisms

• Mechanistic Diversity Exploration:

  • Comparison of sodium-dependent versus proton-dependent ATP synthases

  • Investigation of adaptations in extremophiles (thermophiles, acidophiles, alkaliphiles)

  • Analysis of rotation direction differences between ATP synthases and related V-ATPases

  • Study of mechanistic variations in ATP synthases operating under different pmf magnitudes

• Horizontal Gene Transfer Assessment:

  • Identification of potential horizontal gene transfer events involving atpB

  • Analysis of chimeric ATP synthase complexes resulting from gene transfer

  • Investigation of functional consequences of acquired sequences

  • Reconstruction of evolutionary scenarios explaining current distribution patterns

• Endosymbiotic Integration Analysis:

  • Comparison of bacterial, mitochondrial, and chloroplast atpB

  • Investigation of nuclear versus organellar control of ATP synthase components

  • Assessment of how endosymbiosis shaped ATP synthase structure and regulation

  • Analysis of co-evolution between nuclear and organellar-encoded subunits

These evolutionary studies could reveal how the sophisticated ATP synthase nanomotor emerged and adapted across diverse life forms, potentially inspiring biomimetic energy conversion technologies and deepening our understanding of bioenergetic principles underlying all cellular life.