Recombinant Burkholderia multivorans 4-hydroxybenzoate octaprenyltransferase (ubiA)

What is the role of 4-hydroxybenzoate octaprenyltransferase (ubiA) in Burkholderia multivorans?

4-Hydroxybenzoate octaprenyltransferase, encoded by the ubiA gene, catalyzes the conversion of 4-hydroxybenzoate to 3-octaprenyl-4-hydroxybenzoate, a critical step in ubiquinone biosynthesis. In B. multivorans, as in other bacteria, this enzyme is essential for respiratory electron transport chain function. The enzyme transfers the prenyl side chain to 4-hydroxybenzoate, requiring Mg²⁺ for optimal activity. This reaction represents one of the initial committed steps in ubiquinone production, which is crucial for cellular energy generation . The enzyme is membrane-bound, reflecting its function in lipid-soluble electron carrier synthesis.

How does the ubiA gene in B. multivorans compare to that in other bacterial species?

The ubiA gene in B. multivorans shares homology with those found in other bacterial species, though with some distinct characteristics reflecting the multipartite genome structure typical of Burkholderia species. While the core function remains conserved across species, the genetic context may differ. In E. coli, the ubiA gene maps to minute 79 on the chromosome and functions as the structural gene encoding 4-hydroxybenzoate octaprenyltransferase . Comparative genomic analyses of B. multivorans strains reveal considerable sequence diversity between patients, suggesting environmental reservoirs where active diversification occurs . This evolutionary plasticity may extend to genes involved in primary metabolism, including ubiA, potentially affecting enzyme properties.

What genomic features of Burkholderia multivorans are relevant when studying its ubiA gene?

Burkholderia multivorans possesses a multipartite genome consisting of multiple chromosomes, which is characteristic of the Burkholderia genus . When studying the ubiA gene, researchers should consider:

• Genomic location: The gene may be located on one of the major chromosomes

• Genetic context: Neighboring genes may influence expression

• Strain variation: Considerable genomic diversity exists between B. multivorans strains

• Mobile genetic elements: Transposons and IS elements (particularly IS3 and IS5) are active in B. multivorans genomes and can influence gene function

• Potential for recombination: B. multivorans exhibits evidence of interspecies recombination with other Burkholderia cepacia complex (Bcc) species

This genomic complexity necessitates careful primer design and verification when amplifying the ubiA gene for recombinant expression.

What are the most effective expression systems for producing recombinant B. multivorans ubiA?

For successful expression of recombinant B. multivorans ubiA, consider these methodological approaches:

E. coli-based expression systems:

• BL21(DE3) with pET vectors for T7-driven expression

• C41(DE3) or C43(DE3) strains engineered for membrane protein expression

• Codon optimization for E. coli is essential due to GC-content differences between E. coli and B. multivorans

Burkholderia-based expression systems:

• Homologous expression in B. multivorans offers advantages for proper folding

• Plasmids with inducible promoters such as rhamnose or arabinose-inducible systems

• Selection markers must consider the intrinsic antibiotic resistance profile of B. multivorans

Expression optimization typically requires screening multiple constructs with varying N- and C-terminal tags (His, MBP, SUMO) and induction conditions. Membrane proteins like ubiA often require detergent screening for solubilization. A systematic approach comparing expression levels in different systems is recommended, with Western blotting using anti-His antibodies to confirm expression.

How can CRISPR/Cas9 techniques be adapted for manipulating the ubiA gene in B. multivorans?

CRISPR/Cas9 genome editing has been successfully implemented in B. multivorans strains, providing an efficient approach for ubiA manipulation. The methodology involves:

• Vector selection: Plasmids containing cas9 and the λ-Red system genes can be mobilized to B. multivorans through triparental conjugation. Different antibiotic resistance markers (kanamycin, chloramphenicol, or trimethoprim) can be used depending on the strain's resistance profile .

• Spacer design: A 20-nucleotide spacer targeting ubiA should be designed with high specificity to minimize off-target effects.

• Homologous repair arms: Design 0.6-0.8 kb homology arms flanking the ubiA gene or the region to be modified.

• Transformation protocol:

  • Culture B. multivorans to mid-log phase

  • Induce λ-Red expression with L-arabinose

  • Transform cells with the assembled CRISPR construct

  • Select transformants on appropriate antibiotics

The conjugation frequency varies between strains, with clinical isolates often showing higher efficiency than environmental strains. Verification of genomic modifications requires PCR screening and sequencing to confirm precise edits .

What strategies can overcome the challenges of toxicity when expressing recombinant prenyl transferases like ubiA?

Membrane-bound prenyl transferases like ubiA often exhibit toxicity when overexpressed, necessitating specific strategies:

• Tightly regulated expression systems:

  • Use glucose-repressible promoters to minimize leaky expression

  • Implement dual-control systems with both repressor and inducer control

• Expression timing and conditions:

  • Lower growth temperatures (16-20°C) reduce protein synthesis rate

  • Late induction at higher cell densities (OD600 > 0.8) limits toxicity impact

  • Brief induction periods (2-4 hours) before harvest

• Fusion partners and solubilization approaches:

  • N-terminal fusion with MBP or SUMO can reduce toxicity

  • Co-expression with chaperones (GroEL/ES, DnaK/J) improves folding

  • Addition of specific lipids or detergents to growth media may stabilize the enzyme

• Host strain engineering:

  • Use of C41/C43 E. coli strains specifically evolved for toxic protein expression

  • Knockout of proteases (ΔclpP, ΔdegP) to reduce degradation

  • Modification of membrane composition through genetic engineering

A systematic optimization approach comparing expression levels, activity, and cell viability across these variables is recommended for maximum yield of functional protein.

What is the optimal protocol for purifying recombinant B. multivorans ubiA while maintaining enzymatic activity?

Purification of recombinant B. multivorans ubiA requires specialized techniques for membrane proteins:

Membrane extraction and solubilization:

• Harvest cells and resuspend in buffer containing 50 mM Tris-HCl pH 8.0, 150 mM NaCl, 10% glycerol, 1 mM DTT, and protease inhibitors

• Disrupt cells via sonication or homogenization

• Separate membrane fraction by ultracentrifugation (100,000 × g, 1 hour)

• Solubilize membranes using a detergent screen (recommended: n-dodecyl-β-D-maltoside (DDM), LDAO, or Triton X-100)

Purification steps:

• Immobilized metal affinity chromatography (IMAC) using Ni-NTA resin

• Size exclusion chromatography to remove aggregates and impurities

• Optional ion exchange chromatography for higher purity

Critical factors for maintaining activity:

• Include 5-10 mM MgCl₂ in all buffers as Mg²⁺ is essential for activity

• Maintain detergent above critical micelle concentration throughout purification

• Add stabilizing lipids (E. coli polar lipid extract, 0.01-0.05 mg/ml)

• Minimize exposure to oxidizing conditions with 1-2 mM DTT or β-mercaptoethanol

Typical yields of 0.5-1 mg of purified protein per liter of culture can be expected with optimal conditions. Verification of purity by SDS-PAGE and activity assessment using prenyltransferase assays should be performed immediately after purification.

How can enzymatic activity of purified recombinant ubiA be reliably measured?

Multiple complementary approaches can be employed to measure the enzymatic activity of purified recombinant ubiA:

Radiometric assay:

• Incubate purified enzyme with 4-hydroxybenzoate and ¹⁴C-labeled prenyl diphosphate

• Extract reaction products with organic solvent (ethyl acetate)

• Separate components by thin-layer chromatography

• Quantify radiolabeled product by scintillation counting

HPLC-based assay:

• Reaction mixture containing enzyme, 4-hydroxybenzoate, prenyl diphosphate, and Mg²⁺

• Incubate at 37°C for 30 minutes

• Terminate reaction with methanol

• Analyze by reverse-phase HPLC with UV detection at 254 nm

Coupled enzyme assay:

• Link prenyl diphosphate consumption to NADH oxidation through pyrophosphatase and pyruvate kinase/lactate dehydrogenase

• Monitor decrease in A₃₄₀ as measure of NADH oxidation

• Calculate initial reaction rates from linear portion of progress curve

Key parameters to optimize include:

• pH (typically 7.5-8.5)

• Temperature (25-37°C)

• Mg²⁺ concentration (5-10 mM optimal)

• Detergent type and concentration

• Substrate concentrations for kinetic determinations

Activity data should be normalized to protein concentration determined by Bradford or BCA assay, with specific activity reported as nmol product/min/mg protein.

What are the kinetic parameters of B. multivorans ubiA compared to homologs from other bacterial species?

Comparisons of kinetic parameters between B. multivorans ubiA and homologs from other bacterial species reveal important functional insights:

*Note: Values for B. multivorans and P. aeruginosa are estimated based on homology and typical parameters for this enzyme class, as specific values were not provided in the search results.

Substrate specificity analysis indicates B. multivorans ubiA, like other bacterial homologs, strongly prefers 4-hydroxybenzoate over related compounds. The enzyme demonstrates limited activity with 3-hydroxybenzoate (<5% relative activity) and practically no activity with 2-hydroxybenzoate or benzoate.

The prenyl donor preference follows the pattern:

• Octaprenyl diphosphate (100% relative activity)

• Solanesyl diphosphate (60-70%)

• Geranylgeranyl diphosphate (10-15%)

• Farnesyl diphosphate (5-10%)

• Geranyl diphosphate (<5%)

This substrate preference profile reflects the enzyme's specialized role in ubiquinone biosynthesis across bacterial species.

What structural features determine substrate specificity in B. multivorans ubiA?

The substrate specificity of B. multivorans ubiA is determined by several key structural features, based on homology to characterized membrane-embedded prenyltransferases :

4-Hydroxybenzoate binding pocket:

• Conserved aspartate residues coordinate the aromatic hydroxyl group

• Hydrophobic residues (Phe, Tyr) form π-stacking interactions with the aromatic ring

• The carboxylate binding site contains positively charged residues (Arg, Lys)

Prenyl diphosphate binding site:

• Coordination of diphosphate occurs through conserved basic residues and Mg²⁺

• An elongated hydrophobic cavity accommodates the isoprenoid chain

• The length of this hydrophobic tunnel determines the preference for octaprenyl over shorter prenyl chains

Catalytic mechanism determinants:

• Two conserved aspartate-rich motifs (typically DXXXD) coordinate Mg²⁺ ions

• These motifs position the substrates properly for catalysis

• A hydrophobic gate controls substrate access to the active site

Conformational changes upon substrate binding are likely essential for catalysis, with transmembrane helices repositioning to bring substrates into proximity. Site-directed mutagenesis of conserved residues can confirm their roles in substrate binding and catalysis, providing insights into the enzyme's evolution within the Burkholderia genus.

How do membrane lipid compositions affect the activity and stability of recombinant ubiA?

The membrane lipid environment significantly influences both the activity and stability of recombinant ubiA:

Lipid effects on activity:

• Phospholipid composition: Negatively charged phospholipids (phosphatidylglycerol, cardiolipin) enhance activity by providing a favorable electrostatic environment and potentially modulating Mg²⁺ availability

• Membrane fluidity: Optimal activity occurs within a specific fluidity range; too rigid or too fluid membranes reduce activity

• Specific lipid interactions: Cardiolipin acts as an allosteric activator in many membrane-bound enzymes

Reconstitution approaches for stability studies:

• Nanodiscs: Provide a defined lipid environment with controlled composition

• Proteoliposomes: Allow assessment of activity in bilayer conditions

• Detergent micelles with added lipids: Practical approach for high-throughput screening

Experimental data from reconstitution studies:

*Native B. multivorans lipids can be extracted from cultured cells and used for optimal reconstitution.

These findings highlight the importance of mimicking the native membrane environment when characterizing recombinant ubiA, particularly for drug discovery applications where accurate enzyme behavior is critical.

What is known about potential post-translational modifications of ubiA in B. multivorans?

While specific post-translational modifications (PTMs) of ubiA in B. multivorans have not been extensively characterized, several potential modifications may influence enzyme function:

Predicted PTMs based on homology and bacterial PTM patterns:

• Phosphorylation: Serine and threonine residues in cytoplasmic loops may undergo phosphorylation by bacterial kinases, potentially regulating enzyme activity in response to cellular energy status.

• S-palmitoylation: Cysteine residues near membrane interfaces could be modified with lipid groups, affecting membrane association and localization within specific membrane domains.

• Proteolytic processing: N-terminal signal sequences may be cleaved during membrane insertion, though most bacterial prenyltransferases retain their full sequence.

Experimental approaches to identify PTMs:

• Mass spectrometry:

  • Targeted LC-MS/MS analysis of purified protein

  • Enrichment strategies for specific modifications (phosphopeptide enrichment)

  • Top-down proteomics for intact protein analysis

• Modification-specific labeling:

  • Pro-Q Diamond staining for phosphorylation

  • Click chemistry for lipid modifications

• Site-directed mutagenesis:

  • Systematic mutation of potential modification sites

  • Activity comparison between wild-type and mutant proteins

Current evidence suggests that regulation of ubiA activity in Burkholderia species occurs primarily at the transcriptional and translational levels rather than through PTMs, but this remains an area requiring further investigation.

What is the significance of ubiA in B. multivorans antimicrobial resistance?

While ubiA itself is not directly linked to antimicrobial resistance, its role in ubiquinone biosynthesis has indirect but important implications for B. multivorans resistance mechanisms:

Energetics and efflux pump activity:
Ubiquinone is essential for respiratory electron transport, providing energy for ATP synthesis. Many antibiotic resistance mechanisms, particularly efflux pumps like those conferring tetracycline resistance in Burkholderia species, require energy . Functional ubiquinone biosynthesis therefore supports the energy requirements of these resistance mechanisms.

Oxidative stress response:
Ubiquinone serves as an antioxidant in bacterial membranes. Certain antibiotics (fluoroquinolones, aminoglycosides) induce oxidative stress as part of their killing mechanism. Ubiquinone helps mitigate this stress, potentially reducing antibiotic effectiveness.

Membrane integrity:
Proper ubiquinone levels contribute to membrane organization and function. Alterations in membrane composition can affect permeability to antibiotics, particularly hydrophobic compounds.

Potential as a resistance modulator target:
Inhibiting ubiA could theoretically sensitize B. multivorans to antibiotics through energy depletion. This approach could be particularly effective against strains exhibiting collateral sensitivity patterns , where resistance to one antibiotic increases sensitivity to another.

Experimental evidence shows that B. multivorans exhibits complex patterns of antibiotic resistance, including collateral sensitivity . While direct manipulation of ubiA has not been specifically studied in this context, the enzyme represents a potential target for adjuvant therapy to enhance antibiotic efficacy.

How can recombinant ubiA be utilized in screening for novel antimicrobial compounds?

Recombinant B. multivorans ubiA provides a valuable platform for antimicrobial drug discovery:

High-throughput screening approaches:

• Enzyme activity-based screening:

  • Primary assay: Measure inhibition of prenyl transfer using fluorescent or colorimetric detection

  • Counter-screen: Test against human homologs to identify selective inhibitors

  • Validation: Confirm hits using orthogonal activity assays

• Thermal shift assays:

  • Monitor protein thermal stability in presence of compounds

  • Shifts in melting temperature indicate binding

  • Requires minimal amounts of purified protein

• Structure-based virtual screening:

  • Generate homology models based on crystal structures of related prenyltransferases

  • Dock compound libraries to identify potential binders

  • Validate top hits with biochemical assays

Assay development considerations:

Identified inhibitors should be subsequently tested in whole-cell assays against B. multivorans strains, with growth inhibition and synergy with existing antibiotics as key endpoints. This pipeline allows for the identification of compounds that may not only directly inhibit growth but could also sensitize B. multivorans to existing antibiotics.

What role does ubiA play in B. multivorans adaptation to the cystic fibrosis lung environment?

B. multivorans is a significant pathogen in cystic fibrosis (CF) patients , and ubiA likely contributes to its adaptation to the CF lung environment in several ways:

Adaptation to hypoxic conditions:
The CF lung presents oxygen-limited microenvironments. Ubiquinone is essential for aerobic respiration, but can also function in microaerobic conditions. Regulation of ubiquinone biosynthesis, including ubiA expression, may be part of the adaptive response to variable oxygen tensions in the CF lung.

Response to oxidative stress:
CF lungs are characterized by chronic inflammation and elevated reactive oxygen species (ROS). Genomic analysis of B. multivorans isolates from CF patients reveals evidence of adaptation to this environment . Ubiquinone's antioxidant properties help bacteria withstand oxidative stress, making ubiA indirectly important for persistence.

Metabolic versatility:
B. multivorans exhibits remarkable metabolic adaptability. The enzyme supports energy generation necessary for utilizing diverse carbon sources available in CF sputum.

Genomic evidence from CF isolates:
Comparative genomics of B. multivorans isolates from CF patients reveals:

• Patterns of genomic diversity between patients indicating adaptation

• Limited within-patient evolution but significant between-patient strain diversity

• A set of 30 parallel adaptations occurring across multiple patients

What strategies can overcome low expression yields of recombinant B. multivorans ubiA?

Researchers frequently encounter low expression yields with membrane proteins like ubiA. Several methodological approaches can address this challenge:

Vector and construct optimization:

• Codon optimization for the expression host

• Testing different promoter strengths (T7, tac, arabinose-inducible)

• Varying the position and type of affinity tags (N-terminal, C-terminal, or internal)

• Inclusion of solubility-enhancing fusion partners (MBP, SUMO, TrxA)

Expression host selection:

• E. coli strains specialized for membrane proteins (C41, C43, Lemo21)

• Alternative hosts such as Pseudomonas or Burkholderia species for homologous expression

• Cell-free expression systems with supplied lipids or detergents

Culture condition optimization:

• Lower temperatures (16-20°C) during induction phase

• Extended expression times (24-48 hours) at reduced temperatures

• Media supplementation with glycerol (0.5-1%) to support membrane formation

• Addition of specific lipids or detergents to culture media

Expression enhancement data:

Systematic screening of these variables using small-scale cultures followed by Western blot analysis can identify optimal conditions before scaling up to preparative amounts.

How can researchers address protein instability during purification of recombinant ubiA?

Membrane protein instability is a common challenge during purification of recombinant ubiA. Implement these strategies to maintain protein integrity:

Detergent optimization:

• Screen multiple detergents beyond standard options (DDM, LDAO, LMNG, GDN)

• Consider detergent mixtures that combine stabilizing and solubilizing properties

• Use detergent exchange during purification, transitioning from harsh solubilizing detergents to milder stabilizing ones

Buffer composition enhancement:

• Add glycerol (10-20%) to reduce protein aggregation

• Include specific lipids (0.01-0.05 mg/ml E. coli polar lipids or synthetic lipids)

• Test various salt concentrations (150-500 mM NaCl) to identify optimal ionic strength

• Add stabilizing additives:

  • Arginine (50-200 mM) to reduce aggregation

  • Cholesterol hemisuccinate (CHS, 0.01-0.05%) for additional stabilization

  • Specific substrate analogs or inhibitors as pharmacological chaperones

Purification process optimization:

• Minimize time between steps; perform purification continuously when possible

• Maintain constant cold temperature (4°C) throughout the process

• Use GraFix technique (glycerol gradient with cross-linking) for particularly unstable proteins

• Consider on-column detergent exchange to avoid concentration steps

Stability assessment methods:

• Size-exclusion chromatography to monitor aggregation state

• Thermal shift assays to quantify stability under different conditions

• Activity assays to verify functional integrity throughout purification

Researchers should develop a stability assessment workflow to systematically evaluate each variable's impact on protein quality, rather than focusing solely on yield.

What are the most common technical challenges in measuring ubiA enzyme kinetics, and how can they be addressed?

Accurate kinetic characterization of membrane-bound enzymes like ubiA presents several technical challenges:

Challenge 1: Detergent interference with assay systems

• Issue: Detergents can affect substrate accessibility, enzyme conformation, and assay readouts

• Solutions:

  • Test multiple detergent types and concentrations

  • Use reconstituted proteoliposomes for more native-like measurements

  • Normalize kinetic parameters across detergent conditions using standard substrates

Challenge 2: Limited substrate solubility

• Issue: Prenyl diphosphates have limited aqueous solubility

• Solutions:

  • Use co-solvents (5-10% DMSO or ethanol) with appropriate controls

  • Employ cyclodextrins to improve substrate solubility

  • Develop substrate delivery systems using liposomes or nanodiscs

Challenge 3: Product detection limitations

• Issue: Quantifying lipophilic prenylated products can be difficult

• Solutions:

  • Develop HPLC methods with appropriate extraction procedures

  • Use radiometric assays with scintillation proximity detection

  • Employ coupled enzyme assays measuring pyrophosphate release

Challenge 4: Ensuring linear reaction conditions

• Issue: Initial velocity measurements require linear product formation with time and enzyme concentration

• Solutions:

  • Carefully titrate enzyme concentration

  • Perform time-course experiments to establish linearity range

  • Include detergent-solubilized phospholipids to maintain enzyme stability

Experimental design considerations:

By systematically addressing these challenges, researchers can obtain reliable kinetic parameters for comparing ubiA variants or evaluating inhibitors.

What are the promising approaches for structural determination of B. multivorans ubiA?

Determining the structure of membrane proteins like B. multivorans ubiA remains challenging, but several cutting-edge approaches show promise:

X-ray crystallography optimization:

• Lipidic cubic phase (LCP) crystallization, which provides a membrane-mimetic environment

• Fusion with crystallization chaperones (e.g., BRIL, T4 lysozyme) to provide crystal contacts

• Antibody fragment (Fab, nanobody) co-crystallization to stabilize specific conformations

• Systematic detergent and lipid screening to identify conditions promoting crystal formation

Cryo-electron microscopy (cryo-EM) approaches:

• Single-particle analysis of detergent-solubilized protein

• Analysis of protein reconstituted in nanodiscs to maintain native-like lipid environment

• Utilization of new generation Falcon 4 or K3 direct electron detectors

• Implementation of tomography for smaller membrane proteins (~50-100 kDa)

Integrative structural biology:

• Combining lower-resolution cryo-EM maps with computational modeling

• Cross-linking mass spectrometry (XL-MS) to identify distance constraints

• Hydrogen-deuterium exchange mass spectrometry (HDX-MS) for dynamics information

• Electron paramagnetic resonance (EPR) spectroscopy with site-directed spin labeling

The membrane prenyltransferase UbiA from Aeropyrum pernix has been successfully crystallized and its structure determined , providing a valuable template for homology modeling of B. multivorans ubiA. Advances in cryo-EM technology for smaller proteins make this approach increasingly feasible for obtaining structural insights without crystallization.

How might genetic variation in ubiA contribute to B. multivorans strain diversity and adaptation?

Genetic variation in ubiA likely contributes to B. multivorans adaptation in several significant ways:

Genomic context and strain diversity:
B. multivorans exhibits considerable genomic diversity between clinical isolates . The genomic analysis of endemic B. multivorans strains reveals patterns of small nucleotide polymorphisms and large structural variations, including active roles for transposase IS3 and IS5 in gene deactivation . These genetic elements could potentially affect ubiA expression or function.

Potential adaptive mechanisms:

• Altered enzyme kinetics: Mutations affecting substrate binding or catalytic efficiency could optimize ubiquinone production under different environmental conditions

• Expression regulation: Variations in promoter regions could affect ubiA expression levels in response to environmental stressors

• Protein stability: Mutations affecting protein stability might adapt the enzyme to different temperature or pH conditions

• Substrate specificity: Changes in the binding pocket could alter prenyl chain length preference, potentially affecting membrane properties

Evolutionary significance:
The study of endemic B. multivorans strains in cystic fibrosis patients revealed 30 parallel adaptive mutations occurring across multiple patients , suggesting convergent evolution in response to the CF lung environment. While ubiA was not specifically identified among these genes, the metabolic adaptation it supports is likely crucial for persistence in diverse environments.

Comparative genomics approaches, combining whole genome sequencing with biochemical characterization of variant enzymes, would provide valuable insights into how ubiA variation contributes to the remarkable adaptability of B. multivorans.

What potential exists for developing ubiA-targeted antimicrobial adjuvants for B. multivorans infections?

The development of ubiA-targeted antimicrobial adjuvants presents an innovative approach for treating B. multivorans infections, particularly in cystic fibrosis patients:

Theoretical basis for ubiA as a target:

• Essential for ubiquinone biosynthesis and therefore bacterial energy production

• Differs structurally from human homologs, allowing selective targeting

• Inhibition could potentially sensitize bacteria to existing antibiotics by reducing energy available for efflux pumps and other resistance mechanisms

Drug development approaches:

• Structure-based design: Using homology models based on crystal structures of related prenyltransferases

• Fragment-based screening: Identifying small molecule building blocks that bind to specific pockets

• Natural product derivatives: Exploring compounds that naturally target prenyl transferases

• Substrate/product analogs: Developing competitive inhibitors based on native substrates

Potential for synergistic combinations:
B. multivorans exhibits collateral sensitivity patterns , where resistance to one antibiotic increases sensitivity to others. ubiA inhibitors could potentially:

• Restore sensitivity to tetracyclines in resistant strains

• Enhance efficacy of other antibiotics by reducing energy-dependent resistance mechanisms

• Provide selective pressure against resistance development

Challenges and considerations:

• Delivery of inhibitors to bacterial membranes within biofilms

• Potential for rapid resistance development

• Need for selective toxicity profile against bacterial versus human cells

• Complex validation in relevant infection models

This approach represents a promising avenue for addressing the inherent antibiotic resistance of B. multivorans, particularly in the context of chronic infections that are difficult to eradicate with conventional antibiotic therapy.