Recombinant Brucella melitensis biotype 1 Probable intracellular septation protein A (BMEI0130)

What is BMEI0130 and where is it located in the Brucella melitensis genome?

BMEI0130 is a probable intracellular septation protein A found in Brucella melitensis biotype 1. It is located on chromosome I of the B. melitensis genome. The complete genome sequence of B. melitensis strain 16M has revealed that chromosome I contains 2,117,144 base pairs, while chromosome II contains 1,177,787 base pairs, collectively spanning 3,294,935 base pairs and encoding 3,197 open reading frames (ORFs). The genomic context of BMEI0130 is significant as it provides insights into its evolutionary relationships and functional importance within the organism's cellular processes.

What is the predicted function of BMEI0130 in Brucella melitensis?

Based on sequence homology and structural predictions, BMEI0130 is classified as a probable intracellular septation protein A, suggesting its involvement in cell division processes. As an intracellular septation protein, BMEI0130 likely participates in the formation of the septum during bacterial cell division. The genomic architecture of B. melitensis influences the expression patterns of various genes, including BMEI0130, and may contribute to the regulation of cellular processes like cell division where intracellular septation proteins play crucial roles. While specific experimental validation of BMEI0130's function is still developing, computational analyses suggest its importance in maintaining proper cellular division, which is critical for bacterial survival and pathogenicity.

How does BMEI0130 compare structurally to septation proteins in other bacterial species?

While detailed structural information specific to BMEI0130 is not explicitly provided in the available research, comparative analysis with septation proteins from other bacterial species would likely reveal conserved domains characteristic of proteins involved in bacterial cell division. The distribution of housekeeping genes across both chromosomes in Brucella melitensis includes those involved in essential cellular processes such as DNA replication, transcription, translation, core metabolism, and cell wall biosynthesis. This genomic organization provides context for understanding the evolutionary and functional relationships of BMEI0130 with similar proteins in other bacterial species.

What expression systems have been successfully used for recombinant BMEI0130 production?

Recombinant BMEI0130 protein has been successfully expressed in Escherichia coli expression systems, providing a valuable tool for further biochemical and functional studies. The expression in E. coli demonstrates the protein's compatibility with standard bacterial expression systems, facilitating its production for research purposes. For optimal expression, researchers typically employ vectors with strong promoters (such as T7) and may include affinity tags (like His-tag) to facilitate subsequent purification steps. Expression conditions might require optimization of temperature, inducer concentration, and induction time to maximize the yield of soluble, correctly folded protein.

What are the optimal conditions for purification of recombinant BMEI0130?

While specific purification protocols for BMEI0130 are not detailed in the available search results, standard protein purification methodologies applicable to bacterial recombinant proteins would include:

• Affinity chromatography: If expressed with affinity tags (e.g., His-tag), nickel or cobalt affinity columns can be used for initial capture.

• Ion exchange chromatography: Based on the protein's isoelectric point, anion or cation exchange chromatography can be employed for further purification.

• Size exclusion chromatography: As a final polishing step to remove aggregates and achieve high purity.

For BMEI0130 specifically, researchers should consider buffers that maintain protein solubility and stability, potentially including reducing agents if the protein contains cysteine residues, and protease inhibitors to prevent degradation during the purification process.

What methods can be used to assess the functional activity of purified BMEI0130?

To assess the functional activity of purified BMEI0130, researchers could employ several complementary approaches:

• In vitro septation assays: Monitoring the protein's ability to interact with other components of the bacterial cell division machinery.

• Protein-protein interaction studies: Techniques such as pull-down assays, co-immunoprecipitation, or surface plasmon resonance to identify binding partners.

• Structural studies: X-ray crystallography or NMR spectroscopy to determine the protein's three-dimensional structure and infer functional domains.

• Complementation studies: Introducing the recombinant protein into BMEI0130-deficient strains to assess functional restoration.

These approaches would provide comprehensive insights into the protein's biological activity and functional role in bacterial cell division.

How conserved is BMEI0130 across different Brucella species and biovars?

Based on the genomic organization of Brucella melitensis, we can infer that BMEI0130, being involved in the fundamental process of cell division, likely exhibits conservation across Brucella species. The origins of replication in both Brucella melitensis chromosomes share similarities with other α-proteobacteria, suggesting evolutionary conservation of essential genes.

To properly assess conservation across different Brucella species and biovars, researchers would need to:

• Perform multiple sequence alignments of BMEI0130 homologs

• Calculate sequence identity and similarity percentages

• Analyze the conservation of specific functional domains

• Construct phylogenetic trees to visualize evolutionary relationships

Such analysis would reveal whether BMEI0130 represents a core gene within the Brucella genus or exhibits strain-specific variations that might correlate with differences in virulence or host specificity.

What bioinformatic approaches can be used to predict BMEI0130 structure and function?

Several bioinformatic approaches can be employed to predict BMEI0130 structure and function:

• Homology modeling: Using known structures of homologous septation proteins as templates to predict BMEI0130's three-dimensional structure.

• Domain prediction: Tools like PFAM, SMART, or InterPro to identify functional domains and motifs.

• Secondary structure prediction: Algorithms such as PSIPRED to predict alpha helices, beta sheets, and coiled regions.

• Tertiary structure prediction: Contemporary tools like AlphaFold2 or RoseTTAFold for ab initio structure prediction.

• Functional annotation: Gene Ontology (GO) term analysis and pathway mapping.

• Protein-protein interaction prediction: Computational methods to identify potential binding partners.

These approaches would provide valuable insights into BMEI0130's potential structure-function relationships, guiding experimental design for functional validation studies.

How does the genomic context of BMEI0130 compare to septation proteins in other bacterial pathogens?

The genomic context of BMEI0130 on chromosome I of B. melitensis provides important clues about its functional relationships. The distribution of housekeeping genes across both chromosomes in Brucella melitensis includes those involved in essential cellular processes.

A comparative genomic analysis would typically include:

• Examination of neighboring genes and operonic structure

• Identification of conserved gene clusters across species

• Analysis of regulatory elements in the promoter region

• Comparison with the genomic organization of septation genes in other pathogens

Such analysis would reveal whether the genomic context of BMEI0130 is unique to Brucella or represents a conserved arrangement found in other bacterial pathogens, potentially indicating shared regulatory mechanisms or functional relationships.

What is known about the potential role of BMEI0130 in Brucella melitensis virulence?

While the search results don't explicitly detail BMEI0130's role in virulence, we can infer potential significance based on its function as a septation protein. Proper cell division is essential for bacterial replication within host cells, a critical aspect of Brucella pathogenesis. Research has demonstrated that Brucella melitensis exhibits different gene expression profiles depending on its growth phase, which affects its invasiveness to host cells. Specifically, B. melitensis in the late logarithmic phase of growth demonstrates increased invasiveness compared to mid-logarithmic or stationary growth phases.

Although BMEI0130 was not specifically identified among the differentially expressed genes in the referenced studies, the growth-phase dependent expression patterns observed for other genes suggest potential regulatory mechanisms that might also affect BMEI0130 expression under specific conditions. Further research using gene knockout studies or expression analysis during infection would be necessary to definitively establish BMEI0130's role in virulence.

How does BMEI0130 expression change during different stages of Brucella infection?

A comprehensive study of BMEI0130 expression during infection would require:

• RNA sequencing or quantitative PCR analysis at different time points during infection

• Protein-level expression studies using specific antibodies

• Reporter gene constructs to visualize expression in real-time during infection

• Comparison of expression patterns in different host cell types and tissues

Such studies would provide valuable insights into BMEI0130's potential regulatory patterns during the infection process and might reveal stage-specific functions.

How might inhibition of BMEI0130 affect Brucella melitensis survival and replication in host cells?

As a probable intracellular septation protein involved in bacterial cell division, inhibition of BMEI0130 could potentially disrupt B. melitensis replication within host cells. Septation proteins are essential for the completion of bacterial cell division, and their inhibition often leads to filamentous growth, improper chromosome segregation, or cell death.

The specific effects of BMEI0130 inhibition might include:

• Impaired septum formation during cell division

• Disrupted chromosome segregation

• Formation of elongated, non-dividing cells

• Reduced intracellular bacterial burden

• Attenuated virulence in infection models

Experimental approaches to study these effects could include gene knockdown/knockout studies, treatment with specific inhibitors (if available), or expression of dominant-negative protein variants, followed by assessment of bacterial morphology, replication rates, and virulence.

What gene knockout or knockdown strategies are most effective for studying BMEI0130 function?

For studying BMEI0130 function through gene knockout or knockdown approaches, researchers could employ several strategies, each with distinct advantages:

• Homologous recombination-based gene replacement:

  • Replacing the BMEI0130 gene with an antibiotic resistance marker

  • Advantages: Complete gene deletion; stable modification

  • Challenges: May be lethal if the gene is essential; requires selectable markers

• Conditional knockdown systems:

  • Inducible promoter systems (e.g., tetracycline-regulated)

  • Advantages: Controlled expression; viable even if the gene is essential

  • Challenges: Leaky expression; requires genetic modification

• CRISPR-Cas9 based approaches:

  • Targeted gene editing to introduce frameshift mutations or premature stop codons

  • Advantages: High specificity; relatively rapid implementation

  • Challenges: Potential off-target effects; requires optimization

• Antisense RNA or siRNA strategies:

  • Expression of antisense RNA complementary to BMEI0130 mRNA

  • Advantages: Tunable repression; does not require genome modification

  • Challenges: Incomplete knockdown; variable efficiency

The choice between these strategies would depend on whether BMEI0130 is essential for bacterial viability, available genetic tools for Brucella, and the specific research questions being addressed.

What cellular assays can be used to study the impact of BMEI0130 mutations on Brucella melitensis cell division?

To study the impact of BMEI0130 mutations on B. melitensis cell division, researchers could employ several cellular assays:

• Microscopy-based morphological analysis:

  • Phase contrast or DIC microscopy to observe cell shape and size

  • Fluorescence microscopy with membrane stains to visualize septum formation

  • Electron microscopy for detailed ultrastructural analysis

• Fluorescent protein tagging:

  • Tagging wild-type and mutant BMEI0130 with fluorescent proteins

  • Co-localization studies with other division proteins

  • Time-lapse imaging to monitor dynamic localization during division

• Growth curve analysis:

  • Measuring optical density over time to assess growth rates

  • Colony forming unit (CFU) counts to quantify viable bacteria

  • Comparison of wild-type, mutant, and complemented strains

• Flow cytometry:

  • DNA content analysis to assess chromosome segregation

  • Cell size distribution measurement

  • Membrane integrity assessment

• Live/dead bacterial viability assays:

  • Dual staining with membrane-permeant and impermeant dyes

  • Quantification of viable vs. non-viable cells after mutation

These assays, used in combination, would provide comprehensive insights into how BMEI0130 mutations affect the cell division process in B. melitensis.

What protein-protein interaction methods are most suitable for identifying BMEI0130 binding partners?

Several protein-protein interaction methods are particularly suitable for identifying BMEI0130 binding partners:

• Bacterial two-hybrid system:

  • Advantages: Can be performed in a bacterial host; detects interactions in vivo

  • Limitations: May detect indirect interactions; potential false positives

• Pull-down assays with recombinant tagged BMEI0130:

  • Advantages: Direct biochemical evidence; can identify multiple partners

  • Limitations: May detect non-physiological interactions; requires purified protein

• Co-immunoprecipitation followed by mass spectrometry:

  • Advantages: Can detect native complexes from Brucella; identifies unknown partners

  • Limitations: Requires specific antibodies or epitope tags; may lose transient interactions

• Crosslinking mass spectrometry:

  • Advantages: Captures transient interactions; provides spatial information

  • Limitations: Technical complexity; potential for artifacts

• Surface plasmon resonance (SPR) or bio-layer interferometry:

  • Advantages: Quantitative binding parameters; real-time analysis

  • Limitations: Requires purified candidate partners; artificial environment

• Proximity labeling approaches (BioID, APEX):

  • Advantages: Identifies proximal proteins in living cells; does not require stable interactions

  • Limitations: May label proximal but non-interacting proteins; requires genetic modification

Each method offers distinct advantages, and a combination approach would provide the most comprehensive and reliable identification of BMEI0130 binding partners.

How might structural information about BMEI0130 contribute to antimicrobial drug development?

Detailed structural information about BMEI0130 could significantly contribute to antimicrobial drug development through several avenues:

• Structure-based drug design:

  • Identification of druggable pockets or cavities within the protein structure

  • Virtual screening of chemical libraries against these sites

  • Fragment-based drug discovery approaches targeting specific structural features

• Selectivity analysis:

  • Comparison with human proteins to identify structural differences

  • Design of inhibitors that selectively target bacterial septation proteins

  • Minimization of off-target effects on host proteins

• Mechanism-based inhibitor development:

  • Understanding the catalytic or binding mechanisms of BMEI0130

  • Design of transition-state analogs or competitive inhibitors

  • Development of allosteric modulators targeting regulatory sites

• Rational optimization of lead compounds:

  • Structure-activity relationship studies guided by protein structure

  • Improvement of binding affinity, selectivity, and pharmacokinetic properties

  • Medicinal chemistry optimization based on structural constraints

Given that septation proteins are essential for bacterial viability and absent in mammalian cells, BMEI0130 represents a potentially valuable target for novel antimicrobial development against brucellosis, a disease that remains challenging to treat due to the intracellular lifestyle of the pathogen.

What are the most promising approaches for developing BMEI0130-specific antibodies for research applications?

Developing BMEI0130-specific antibodies for research applications could employ several promising approaches:

• Recombinant protein immunization:

  • Expression and purification of full-length BMEI0130 or specific domains

  • Immunization in rabbits, mice, or other suitable host species

  • Advantages: High antigen purity; potentially high antibody specificity

• Synthetic peptide approach:

  • Bioinformatic identification of antigenic epitopes

  • Synthesis of peptides corresponding to these regions

  • Conjugation to carrier proteins (e.g., KLH or BSA) for immunization

  • Advantages: Targeted approach; can generate antibodies to specific domains

• Genetic immunization:

  • DNA vaccination with BMEI0130-encoding plasmids

  • In vivo expression and presentation of the antigen

  • Advantages: Native protein folding; no need for protein purification

• Phage display technology:

  • Generation of recombinant antibody libraries

  • Selection against purified BMEI0130 protein

  • Advantages: Fully in vitro process; no animal immunization required

• Monoclonal vs. polyclonal considerations:

  • Polyclonal: Recognizes multiple epitopes; higher sensitivity; easier production

  • Monoclonal: Single epitope specificity; higher reproducibility; consistent supply

The choice of approach would depend on the intended application, whether structural studies, localization, or functional analyses, as well as considerations of specificity, sensitivity, and cross-reactivity with related bacterial proteins.

How might comparative analysis of BMEI0130 across different Brucella strains inform vaccine development strategies?

Comparative analysis of BMEI0130 across different Brucella strains could significantly inform vaccine development strategies through several mechanisms:

• Identification of conserved epitopes:

  • Analysis of sequence conservation across strains and species

  • Identification of invariant regions as potential vaccine targets

  • Development of broadly protective vaccines against multiple Brucella species

• Correlation with attenuation:

  • Comparison between virulent field strains and attenuated vaccine strains like Rev.1

  • Identification of mutations that correlate with reduced virulence

  • Understanding the contribution of BMEI0130 variants to attenuation

• Strain-specific markers:

  • Identification of BMEI0130 sequence variations that could serve as diagnostic markers

  • Development of PCR-based assays to distinguish vaccine strains from field isolates

  • Implementation in post-vaccination surveillance programs

• Structure-function insights:

  • Understanding how sequence variations affect protein function

  • Rational design of mutations that attenuate virulence while maintaining immunogenicity

  • Development of novel live attenuated vaccine candidates

Such comparative analyses would be particularly valuable given the challenges associated with current Brucella vaccines, including the Rev.1 strain which, while effective, "is not attenuated enough; it usually causes abortion in vaccinated animals and can infect human" . A better understanding of BMEI0130 variation could potentially contribute to the development of safer and more effective vaccines.

What are the common challenges in expressing and purifying recombinant BMEI0130, and how can they be addressed?

Common challenges in expressing and purifying recombinant BMEI0130 may include:

• Protein solubility issues:

  • Challenge: Formation of inclusion bodies in E. coli expression systems

  • Solutions:

    • Lower expression temperature (16-25°C)

    • Use solubility-enhancing fusion tags (MBP, SUMO, TrxA)

    • Optimize inducer concentration for slower expression

    • Expression in specialized E. coli strains (e.g., Arctic Express, Rosetta)

• Protein stability concerns:

  • Challenge: Degradation during expression or purification

  • Solutions:

    • Include protease inhibitors throughout purification

    • Optimize buffer conditions (pH, salt concentration)

    • Identify and eliminate proteolytic cleavage sites

    • Maintain samples at 4°C during processing

• Purification difficulties:

  • Challenge: Co-purification of contaminants or bacterial proteins

  • Solutions:

    • Multiple orthogonal purification steps

    • On-column refolding if necessary

    • Size exclusion chromatography as a final polishing step

    • Removal of fusion tags after purification

• Functional activity retention:

  • Challenge: Loss of activity during purification

  • Solutions:

    • Include stabilizing cofactors or ligands

    • Avoid harsh elution conditions

    • Monitor activity throughout purification process

    • Optimize storage conditions (glycerol, reducing agents)

While specific information about BMEI0130 expression challenges is not provided in the search results, recombinant BMEI0130 protein has been successfully expressed in Escherichia coli expression systems, indicating that these challenges can be overcome with appropriate optimization.

What are the key considerations for designing primers for BMEI0130 amplification and mutagenesis?

When designing primers for BMEI0130 amplification and mutagenesis, researchers should consider several key factors:

• Primer specificity:

  • Design primers unique to BMEI0130 to avoid amplification of homologous genes

  • Perform in silico PCR analysis against the complete Brucella genome

  • Consider primer length (typically 18-30 nucleotides) for optimal specificity

• For cloning applications:

  • Include appropriate restriction enzyme sites with buffer sequences

  • Maintain the reading frame for in-frame fusion with tags

  • Consider codon optimization for the expression host

• For site-directed mutagenesis:

  • Position mutations centrally within the primer

  • Ensure sufficient complementary sequence (10-15 bp) on both sides of the mutation

  • Check for potential secondary structures or primer-dimer formation

  • Verify similar melting temperatures for forward and reverse primers

• For overlap extension PCR:

  • Design primers with complementary overlapping regions (15-20 bp)

  • Ensure similar GC content and Tm across all primers

  • Avoid placing overlaps in regions with complex secondary structure

• General considerations:

  • Aim for GC content between 40-60%

  • Avoid runs of identical nucleotides (especially >4 Gs)

  • Check for self-complementarity

  • Ensure 3' ends are stable but not too GC-rich

These design principles would help ensure successful amplification and mutagenesis of BMEI0130 for various research applications.

What control experiments should be included when studying BMEI0130 function in vitro and in vivo?

When studying BMEI0130 function, several critical control experiments should be included:

• For in vitro protein studies:

  • Negative controls: Buffer-only or irrelevant protein controls

  • Positive controls: Known functional homologs from related species

  • Heat-inactivated BMEI0130 to confirm activity is protein-dependent

  • Titration series to establish dose-dependent effects

  • Site-directed mutants targeting predicted functional residues

• For gene expression studies:

  • Housekeeping gene controls for normalization

  • Positive control genes known to be regulated under test conditions

  • Time course analysis to capture dynamic expression changes

  • Multiple biological and technical replicates

• For genetic manipulation studies:

  • Empty vector controls

  • Complementation with wild-type BMEI0130 to confirm phenotype specificity

  • Complementation with site-directed mutants to identify critical residues

  • Conditional expression systems to assess dose-dependent effects

• For in vivo infection studies:

  • Wild-type Brucella control

  • Known attenuated strain as positive control for attenuation

  • Multiple infection time points

  • Assessment of bacterial burden in different tissues

  • Measurement of both bacterial replication and host responses

• Technical validation:

  • Western blot or other protein detection to confirm expression/deletion

  • Sequencing validation of genetic constructs

  • Growth curves to assess general fitness effects

  • Microscopy to confirm expected subcellular localization

These control experiments would ensure that any observed phenotypes are specifically attributable to BMEI0130 function rather than experimental artifacts or secondary effects.

How might systems biology approaches contribute to our understanding of BMEI0130's role in Brucella melitensis biology?

Systems biology approaches offer powerful frameworks for understanding BMEI0130's role within the broader context of Brucella melitensis biology:

• Network analysis:

  • Integration of protein-protein interaction data

  • Identification of BMEI0130's position within cellular interaction networks

  • Prediction of functional relationships based on network proximity

  • Identification of key hub proteins that interact with BMEI0130

• Multi-omics integration:

  • Correlation of BMEI0130 expression with global transcriptomic profiles

  • Proteomic analysis of changes induced by BMEI0130 mutation

  • Metabolomic profiling to identify pathways affected by BMEI0130 function

  • Integration of genomic, transcriptomic, proteomic, and metabolomic data

• Computational modeling:

  • Flux balance analysis to predict metabolic impacts of BMEI0130 dysfunction

  • Agent-based modeling of cell division processes

  • Simulation of septation dynamics under various conditions

  • Prediction of emergent properties from molecular interactions

• Machine learning applications:

  • Pattern recognition in experimental data related to BMEI0130

  • Prediction of functional partners based on co-expression data

  • Identification of environmental conditions affecting BMEI0130 function

  • Classification of phenotypic effects based on mutation patterns

These approaches would provide a holistic understanding of how BMEI0130 integrates into the broader cellular processes of B. melitensis, potentially revealing unexpected connections to other aspects of bacterial physiology and pathogenesis.

What potential applications exist for BMEI0130 in biotechnology beyond understanding Brucella pathogenesis?

Beyond understanding Brucella pathogenesis, BMEI0130 might have several potential biotechnological applications:

• Biomarker development:

  • Diagnostic tool development for brucellosis detection

  • Differentiation between vaccinated and infected animals

  • Strain typing and epidemiological surveillance

• Protein engineering applications:

  • Development of temperature-sensitive variants for controlled bacterial growth

  • Engineering of septation mechanisms for synthetic biology applications

  • Creation of programmable bacterial cell division systems

• Antimicrobial technology:

  • Drug target for novel anti-Brucella therapeutics

  • Screening platform for antimicrobial compound discovery

  • Development of protein-based antibacterial strategies

• Vaccine development:

  • Component of subunit vaccines against brucellosis

  • Attenuating target for development of live vaccine strains

  • Carrier protein for delivery of heterologous antigens

• Research tools:

  • Molecular probes for studying bacterial cell division

  • Model system for understanding septation in intracellular pathogens

  • Educational tool for demonstrating evolutionary conservation of cell division

These applications would leverage the unique properties of BMEI0130 and its critical role in bacterial cell division to develop biotechnological tools with broader impacts beyond basic pathogenesis research.

How might CRISPR-Cas9 technology be applied to study BMEI0130 function in Brucella melitensis?

CRISPR-Cas9 technology offers several innovative approaches to study BMEI0130 function in Brucella melitensis:

• Precise gene editing:

  • Generation of clean deletions without antibiotic markers

  • Introduction of point mutations to study specific functional residues

  • Creation of domain deletions to assess modular protein function

  • Scarless editing to avoid polar effects on adjacent genes

• Transcriptional modulation:

  • CRISPRi (dCas9) for reversible gene repression without DNA modification

  • CRISPRa for upregulation to assess overexpression phenotypes

  • Timed repression using inducible systems to study temporal requirements

  • Gradient repression to determine minimal functional expression levels

• Protein tagging:

  • In-frame insertion of fluorescent proteins or epitope tags

  • Creation of fusion proteins for localization studies

  • Insertion of proximity labeling tags (BioID, APEX) to identify interaction partners

  • Development of degron-tagged versions for controlled protein degradation

• High-throughput functional genomics:

  • CRISPR screens to identify genetic interactions with BMEI0130

  • Saturating mutagenesis to map functional domains with single-amino acid resolution

  • Paired-guide approaches to study combinatorial genetic interactions

  • Base editing to introduce specific codon changes without double-strand breaks

• In vivo applications:

  • Tracking BMEI0130-edited strains during infection

  • Competition assays between wild-type and edited strains

  • Tissue-specific behavior of mutant strains

  • Host response to BMEI0130 variants