Recombinant Bordetella petrii ATP synthase subunit b (atpF)

How does B. petrii relate evolutionarily to other Bordetella species, and why is this relevant to ATP synthase studies?

Bordetella petrii represents a unique evolutionary position in the Bordetella genus. It is considered the environmental progenitor of pathogenic bordetellae and is the only Bordetella strain not known to have a close pathogenic, opportunistic, or commensal relationship with an animal or human host . This environmental bacterium is capable of anaerobic growth, distinguishing it from many other Bordetella species .

The evolutionary relationship within the genus has been established through multiple analyses including:

• Comparative 16S rDNA sequence analysis

• DNA base composition

• Isoprenoid quinone content

• DNA-DNA hybridization experiments

• Metabolic properties

This evolutionary context is crucial for ATP synthase studies as the atpF gene may reveal adaptations associated with environmental versus host-associated lifestyles. Comparative analyses of ATP synthase components across Bordetella species can provide insights into how this essential enzyme complex has evolved during the transition from environmental to pathogenic niches, potentially revealing mechanisms of adaptation to different energy requirements.

What are the optimal storage and handling conditions for Recombinant Bordetella petrii ATP synthase subunit b (atpF)?

Optimal storage conditions depend on the formulation of the recombinant protein:

For long-term storage, it is recommended to aliquot the protein to avoid repeated freeze-thaw cycles, which can compromise protein integrity and activity . The protein stability is influenced by multiple factors including buffer ingredients, storage temperature, and intrinsic properties of the protein itself .

What is the recommended reconstitution protocol for Recombinant Bordetella petrii ATP synthase subunit b (atpF)?

For optimal reconstitution of lyophilized Recombinant Bordetella petrii ATP synthase subunit b:

• Briefly centrifuge the vial prior to opening to bring contents to the bottom

• Reconstitute the protein in deionized sterile water to a concentration of 0.1-1.0 mg/mL

• Add glycerol to a final concentration of 5-50% (50% is typically recommended) to prevent freeze-thaw damage during subsequent storage

• Aliquot for long-term storage at -20°C/-80°C

The reconstituted protein is typically stored in a Tris/PBS-based buffer containing 6% Trehalose at pH 8.0 to maintain stability . This formulation helps preserve protein structure and function during freeze-thaw cycles.

How can researchers verify the purity and activity of Recombinant Bordetella petrii ATP synthase subunit b?

Verification of protein purity and activity involves multiple complementary techniques:

Purity Assessment:

• SDS-PAGE analysis (standard purity is >85-90%)

• Western blotting using anti-His antibodies to detect the His-tagged protein

• Size exclusion chromatography to confirm homogeneity

Activity Verification:

• ATP hydrolysis assays when incorporated into the complete ATP synthase complex

• Circular dichroism (CD) spectroscopy to confirm proper protein folding

• Thermal shift assays to assess protein stability

• In vitro reconstitution with other ATP synthase subunits to test complex formation

To maintain reproducibility across experiments, researchers should document batch-to-batch variations in purity and activity and standardize protein concentrations based on activity assays rather than total protein content.

What approaches can be used to study the structure-function relationship of Bordetella petrii ATP synthase subunit b?

Investigating structure-function relationships of ATP synthase subunit b requires multidisciplinary approaches:

Structural Analysis:

• X-ray crystallography of the isolated subunit or reconstructed F₀ complex

• Cryo-electron microscopy of the entire ATP synthase complex

• NMR spectroscopy for dynamic structural elements

• Molecular dynamics simulations based on homology models

Functional Analysis:

• Site-directed mutagenesis of conserved residues

• Cross-linking studies to identify interaction partners within the ATP synthase complex

• Reconstitution of mutant proteins into proteoliposomes for function testing

• ATP synthesis/hydrolysis assays with reconstituted complexes

The membrane-spanning nature of this protein presents particular challenges for structural studies. Researchers often employ detergent solubilization or nanodiscs to maintain protein stability during purification and analysis. Comparative analysis with better-characterized ATP synthase subunits from model organisms like E. coli can provide valuable insights into conserved functional domains.

How does the Bordetella petrii ATP synthase compare to those of pathogenic Bordetella species in terms of adaptation and evolution?

The evolutionary adaptation of ATP synthase across Bordetella species reflects their adaptation to different ecological niches. Bordetella petrii, as the environmental progenitor of pathogenic bordetellae, likely possesses adaptations for versatile energy metabolism in fluctuating environmental conditions, including the ability to function under anaerobic conditions .

Comparative analysis reveals:

Genome sequence analyses have shown that while B. pertussis and B. parapertussis have undergone substantial gene deletion and pseudogene formation during host adaptation, genes involved in central metabolism are largely conserved . This suggests that ATP synthase functionality remains critical even as these pathogens adapted to specialized host niches.

What role might ATP synthase play in the anaerobic metabolism capabilities of Bordetella petrii?

Bordetella petrii's unique capability for anaerobic growth among Bordetella species suggests specialized adaptations in its energy metabolism machinery, including ATP synthase . Under anaerobic conditions, several potential mechanisms may be at play:

• Modified proton gradient generation: In the absence of oxygen as a terminal electron acceptor, B. petrii may use alternative electron acceptors (nitrate, fumarate, etc.) that generate weaker proton gradients, potentially requiring adaptations in ATP synthase efficiency.

• Reverse operation capability: Under certain anaerobic conditions, ATP synthase can operate in reverse, hydrolyzing ATP to maintain proton gradient for other cellular processes.

• Structural adaptations: The atpF gene product may contain specific modifications that allow optimal ATP synthase assembly and function under low oxygen conditions.

• Regulatory mechanisms: Expression and activity of ATP synthase components may be differentially regulated under aerobic versus anaerobic conditions.

Experimental approaches to investigate these aspects include:

• Comparative growth studies under aerobic vs. anaerobic conditions with ATP synthase inhibitors

• Gene expression analysis to determine if atpF expression is oxygen-dependent

• Biochemical characterization of ATP synthase activity under varying oxygen tensions

• Structural studies to identify potential adaptations in subunit b that facilitate anaerobic energy conservation

What are common challenges in working with Recombinant Bordetella petrii ATP synthase subunit b and how can they be addressed?

Researchers working with Recombinant Bordetella petrii ATP synthase subunit b often encounter several challenges:

To ensure experimental reproducibility, researchers should standardize protocols for expression, purification, and storage. Each new batch of protein should undergo quality control testing for purity, structural integrity, and functional activity before use in experiments .

How can researchers design experiments to investigate the role of ATP synthase in Bordetella petrii's environmental adaptation?

To elucidate the role of ATP synthase in B. petrii's environmental adaptation, researchers should design experiments that compare its function across various conditions that mimic environmental stresses:

Experimental Design Framework:

• Comparative genomics approach:

  • Compare atpF sequences across Bordetella species to identify unique features in B. petrii

  • Analyze conservation patterns of ATP synthase genes in relation to environmental versus host-adapted species

• Expression analysis under varying conditions:

  • Measure atpF expression levels under aerobic vs. anaerobic conditions

  • Test expression responses to nutrient limitation, pH changes, and temperature stress

  • Use quantitative PCR or RNA-seq to measure transcriptional changes

• Functional characterization:

  • Generate atpF mutants and assess growth under various environmental conditions

  • Measure ATP production capacity in wild-type vs. mutant strains

  • Compare ATP synthase activity in membrane preparations under different pH, temperature, and ionic conditions

• Structural studies:

  • Perform comparative modeling of B. petrii ATP synthase subunit b against homologs

  • Identify structural features that might contribute to environmental versatility

This multifaceted approach can reveal how ATP synthase contributes to B. petrii's unique ability to thrive in diverse environmental conditions, potentially providing insights into the evolution of energy metabolism during the transition from environmental to host-adapted lifestyles within the Bordetella genus .

What are emerging research questions regarding Bordetella petrii ATP synthase in the context of bacterial evolution and adaptation?

Several cutting-edge research directions emerge from our current understanding of Bordetella petrii ATP synthase:

• Evolutionary transitions: How did ATP synthase components evolve during the transition from environmental B. petrii to host-adapted Bordetella species? This could reveal mechanisms of metabolic adaptation during host restriction.

• Environmental sensing: Does ATP synthase in B. petrii function as more than an energy-generating complex? Recent research in other bacteria suggests ATP synthase may participate in environmental sensing and stress responses.

• Anaerobic adaptation: What specific modifications in ATP synthase components enable B. petrii to function under anaerobic conditions, and how do these compare to other facultative anaerobes?

• Cross-species comparative analysis: How do ATP synthase components from B. petrii compare functionally to those of other Bordetella species in reconstituted systems? This could reveal functional changes that accompanied host adaptation.

• Regulatory networks: How is atpF expression regulated in response to environmental signals, and how does this regulation differ from host-adapted Bordetella species?

These research questions could be addressed using emerging technologies such as cryo-EM for structural determination, systems biology approaches to understand regulatory networks, and genome editing tools to generate precise mutations for functional studies.

How might research on Recombinant Bordetella petrii ATP synthase subunit b contribute to understanding bacterial energy metabolism evolution?

Research on Bordetella petrii ATP synthase subunit b provides a unique window into the evolution of bacterial energy metabolism during the transition from environmental to pathogenic lifestyles:

• Transitional model: As the proposed environmental progenitor of pathogenic bordetellae , B. petrii represents an evolutionary intermediate that can illuminate how ATP synthase adapted during host specialization.

• Metabolic flexibility: The ability of B. petrii to grow anaerobically suggests its ATP synthase may have features enabling function across varying energy states, potentially representing an ancestral state of metabolic flexibility.

• Comparative framework: The close genetic relationship yet distinct ecological niches of Bordetella species provides an excellent model system for studying how cellular energy machinery evolves during host adaptation.

• Genetic conservation patterns: While B. pertussis and B. parapertussis have undergone substantial gene deletion and pseudogene formation during host adaptation, genes involved in central metabolism including ATP synthesis are largely conserved , suggesting fundamental constraints on energy metabolism evolution.

Researchers can leverage these unique aspects of Bordetella evolution to develop broader principles about how core metabolic machinery adapts during pathogen evolution, potentially revealing new insights into the minimal requirements for cellular energy production across different ecological niches.