Recombinant Agrobacterium vitis Membrane protein insertase YidC (yidC)
Description
Introduction to Recombinant Agrobacterium vitis Membrane Protein Insertase YidC
Recombinant Agrobacterium vitis Membrane protein insertase YidC (yidC) is a full-length protein consisting of 620 amino acids that functions as a critical component in bacterial membrane protein integration systems. This protein belongs to the evolutionarily conserved YidC/Oxa1/Alb3 family, which is found across bacteria, mitochondria, and chloroplasts . The recombinant form is typically expressed in Escherichia coli with a histidine tag to facilitate purification and subsequent research applications .
The source organism, Agrobacterium vitis, is primarily known as a bacterial pathogen that causes crown gall disease in grapevines worldwide . While most research on membrane insertases has focused on Escherichia coli and other model organisms, the Agrobacterium vitis variant offers unique insights into protein translocation mechanisms in plant pathogens, making it valuable for both basic science and agricultural applications.
Physical and Biochemical Properties
The recombinant protein is typically supplied in a lyophilized form and requires reconstitution in deionized sterile water to a concentration of 0.1-1.0 mg/mL for experimental use. Addition of 5-50% glycerol is recommended for long-term storage to maintain stability .
Membrane Protein Integration Functions
The primary function of Agrobacterium vitis YidC, like other YidC family members, is to facilitate the integration of proteins into the bacterial membrane. This protein functions through two distinct mechanisms:
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As an independent insertase: YidC can directly integrate certain membrane proteins into the lipid bilayer without requiring the Sec translocase machinery . Research has demonstrated that purified YidC reconstituted into proteoliposomes can efficiently support the membrane insertion of Sec-independent proteins such as the Pf3 coat protein . This suggests that YidC acts as a catalytic enzyme facilitating membrane insertion.
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As a membrane protein chaperone: YidC also works cooperatively with the Sec translocase to assist in the folding and assembly of membrane proteins during the insertion process . In this capacity, it helps transfer transmembrane regions of substrate proteins into the hydrophobic bilayer.
Recombinant Expression Systems
The production of recombinant Agrobacterium vitis YidC typically employs Escherichia coli expression systems. The gene encoding full-length yidC is cloned into suitable expression vectors such as pBAD Myc-His A or pET-16 with affinity tags to facilitate purification . Common expression strains include E. coli C43(DE3), which are particularly effective for membrane protein expression.
The expression protocol generally involves:
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Transforming the expression plasmid into the host strain
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Growing bacterial cultures at 37°C until reaching appropriate density
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Inducing protein expression with specific inducers (e.g., 0.2% L-(+)-arabinose or IPTG)
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Additional incubation for protein accumulation
Purification Techniques
The purification of recombinant Agrobacterium vitis YidC involves several critical steps:
| Step | Procedure | Details |
|---|---|---|
| 1 | Cell lysis | Mechanical disruption (e.g., microfluidizer) in buffer containing glycerol |
| 2 | Membrane extraction | Solubilization using detergents such as n-decyl β-d maltopyranoside (DM) |
| 3 | Affinity chromatography | Nickel affinity columns for His-tagged protein capture |
| 4 | Tag cleavage (optional) | Using specific proteases (e.g., 3C rhinovirus protease) |
| 5 | Size exclusion chromatography | Gel filtration (e.g., Superdex-200) for further purification |
| 6 | Ion exchange | Final purification step (e.g., Mono-Q) |
| 7 | Concentration | Concentration to 5-10 mg/ml using appropriate molecular weight cutoff devices |
This purification process yields highly pure protein suitable for structural and functional studies . The purified protein is typically maintained in buffers containing detergents to preserve the native conformation of this membrane protein.
Antimicrobial Research Applications
YidC proteins have emerged as potential targets for novel antibacterial agents due to their essential role in bacterial viability. Research has demonstrated that downregulation of yidC in bacteria results in impaired growth, suggesting its potential as a therapeutic target . Specifically, antisense RNA-mediated silencing of yidC in Escherichia coli has been shown to sensitize bacteria to antibacterial essential oils like eugenol and carvacrol, demonstrating a synergistic effect that could be exploited for antimicrobial development .
The recombinant A. vitis YidC provides a valuable tool for screening potential YidC inhibitors that could lead to new classes of antibiotics targeting plant pathogens like Agrobacterium vitis, which cause significant agricultural damage worldwide.
Agricultural and Biotechnological Significance
Understanding the function of Agrobacterium vitis YidC has implications for controlling crown gall disease in grapevines. As A. vitis is the primary causal agent of this economically significant disease , targeting its essential proteins like YidC could potentially lead to new strategies for disease management.
Additionally, insights from studying YidC function may contribute to the development of improved protein production systems in biotechnology. Research on YidC homologs in other species has demonstrated that these proteins influence the capacity of bacteria to secrete recombinant proteins , suggesting potential applications in optimizing bacterial expression systems for commercial protein production.
Evolutionary Conservation and Variation
| Species | Key Differences | Functional Implications |
|---|---|---|
| Escherichia coli YidC | Well-characterized structure with five core transmembrane helices | Functions as both insertase and Sec-associated chaperone |
| Bacillus halodurans YidC | Lacks the periplasmic domain present in A. vitis YidC | May have altered substrate specificity |
| Rhodopirellula baltica YidC | Extended positively charged C-terminal region | Enhanced ribosome binding capability |
| Oceanicaulis alexandrii YidC | Extended C-terminal region | Can compensate for loss of SRP-receptor function |
The variations among these proteins highlight the evolutionary adaptations that may reflect species-specific requirements for membrane protein integration .
Functional Comparison in Different Bacterial Contexts
Comparative functional studies have revealed that while the core mechanisms of YidC proteins are conserved, their specific roles may vary between species. In Lactococcus lactis, for example, there are two YidC paralogs (YidC1 and YidC2) with distinct functional impacts - deletion of YidC2 significantly decreases biomass, electroporation efficiency, and ATP synthase activity, while YidC1 deletion has minimal effects .
The Agrobacterium vitis YidC likely has adapted to optimize insertion of proteins relevant to its plant-associated lifestyle, potentially including virulence factors or proteins involved in plant-microbe interactions, though specific substrates unique to A. vitis YidC await detailed characterization.
Substrate Specificity Exploration
Identifying the specific substrate proteins that preferentially interact with Agrobacterium vitis YidC could reveal unique aspects of membrane protein biogenesis in this plant pathogen. Particularly interesting would be studies examining whether virulence factors or other proteins associated with pathogenicity are dependent on YidC for proper membrane integration .
Therapeutic Target Development
Building on findings that YidC depletion sensitizes bacteria to certain antimicrobial compounds, further research could explore the development of specific inhibitors targeting Agrobacterium vitis YidC . Such inhibitors could potentially serve as novel agricultural treatments for controlling crown gall disease while minimizing impacts on beneficial microorganisms.
Product Specs
Note: We prioritize shipping the format currently in stock. However, if you have specific format requirements, please indicate them during order placement, and we will accommodate your needs.
Note: All protein shipments are standardly accompanied by blue ice packs. If you require dry ice shipping, please inform us in advance, as additional fees will apply.
Generally, liquid form has a shelf life of 6 months at -20°C/-80°C. Lyophilized form has a shelf life of 12 months at -20°C/-80°C.
Target Background
KEGG: avi:Avi_0455
STRING: 311402.Avi_0455
Q&A
What is the genomic context of yidC in Agrobacterium vitis?
The yidC gene in A. vitis is located within a highly conserved gene cluster found in many Gram-negative bacteria. Similar to E. coli, this cluster maintains the gene order rpmH, rnpA, yidD, yidC, and trmE . This conservation suggests functional importance in protein synthesis and membrane targeting processes. The yidC gene is typically positioned just 2 bp downstream of yidD, with yidD overlapping rnpA by approximately 37 bp in related bacteria . This tight organization may facilitate coordinated expression of these genes, potentially through polycistronic mRNA transcription originating from promoters upstream of rpmH .
How does YidC function in bacterial membrane protein insertion?
YidC functions as a membrane protein insertase that facilitates the integration of proteins into the bacterial inner membrane. In E. coli, YidC has been shown to operate through both Sec-dependent and Sec-independent pathways . When working with the Sec translocon, YidC assists in lateral transfer of transmembrane domains from the translocon to the lipid bilayer and aids in proper folding. In the Sec-independent pathway, YidC directly mediates the insertion of small membrane proteins. Cross-linking experiments have demonstrated that YidD, a protein encoded by a gene immediately upstream of yidC, is positioned in proximity to nascent membrane proteins during their localization in the Sec-YidC translocon, suggesting potential cooperation between these proteins in the insertion process .
What is the relationship between A. vitis pathogenicity and membrane proteins?
A. vitis is the primary causal agent of grapevine crown gall disease worldwide, characterized by tumor formation on aerial plant parts . Its pathogenicity is largely determined by a tumor-inducing (Ti) plasmid that enables the transfer of T-DNA into the plant genome . While the direct relationship between YidC and virulence has not been explicitly established in the provided research, membrane proteins are critical for bacterial pathogenicity through multiple mechanisms: (1) facilitating host-pathogen interactions, (2) mediating secretion of virulence factors, and (3) enabling adaptation to host environments. Given that YidC is essential for proper membrane protein insertion, it likely plays an indirect but crucial role in maintaining virulence factor functionality in A. vitis.
What PCR-based approaches can effectively detect and differentiate A. vitis strains for YidC research?
When isolating A. vitis for YidC studies, reliable detection and differentiation of strains is essential. PCR-based methods have proven effective for this purpose. Multiple primer sets have been evaluated for their specificity and reproducibility in detecting pathogenic strains:
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virD2A/2C primer set can detect the virD2 region of the Ti plasmid
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A multiplex PCR approach using virFF1/virFR2 and virD2S4F/virD2S4R can detect virF and virD2 regions in the common opine types (nopaline, octopine, vitopine) of A. vitis
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PGF/PGR, a polygalacturonase-specific primer set, can identify A. vitis strains and differentiate them from A. tumefaciens
For optimal results in Bio-PCR protocols, bacteria should be extracted from vascular tissue of galls, crown, roots, or canes by suspension in sterile distilled water, followed by dilution series preparation. This approach enables specific isolation of A. vitis strains for subsequent yidC cloning and characterization experiments .
How can researchers evaluate the role of YidC in membrane protein insertion in A. vitis?
To investigate YidC function in A. vitis, researchers can employ several complementary approaches:
Each methodology should include appropriate controls, such as parallel experiments with E. coli YidC, to distinguish A. vitis-specific functions from general bacterial membrane insertion processes.
What expression systems are optimal for recombinant A. vitis YidC production?
The choice of expression system for recombinant A. vitis YidC should consider the protein's membrane-bound nature and potential toxicity when overexpressed. Based on general principles for membrane protein expression:
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E. coli-based systems:
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C41(DE3) or C43(DE3) strains are engineered specifically for membrane protein expression
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LEMO21(DE3) strain allows tunable expression through rhamnose-regulated T7 lysozyme production
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Expression at lower temperatures (16-25°C) often improves folding of membrane proteins
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Alternative bacterial hosts:
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Lactococcus lactis may provide a gram-positive expression environment with less proteolytic activity
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Agrobacterium tumefaciens-based expression could offer a more native-like membrane environment
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Cell-free expression systems:
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Allow direct incorporation into artificial liposomes or nanodiscs
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Avoid toxicity issues associated with in vivo expression
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Enable incorporation of non-natural amino acids for biophysical studies
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For optimal results, the yidC gene should be amplified using high-fidelity PCR techniques similar to those used for 16S rRNA gene amplification in Agrobacterium studies, using appropriate reaction conditions (1x HF-buffer, dNTPs, primers, and polymerase) .
How do YidC and YidD interact in A. vitis compared to other bacterial systems?
For A. vitis research, several experimental approaches could elucidate this interaction:
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Co-immunoprecipitation studies with tagged YidC and YidD proteins
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Bacterial two-hybrid assays to confirm direct interaction
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Comparative phenotypic analysis of ΔyidD versus ΔyidC mutants in A. vitis
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Structural studies examining potential binding interfaces
The high conservation of the yidC-yidD genomic arrangement in Gram-negative bacteria suggests evolutionary significance to their potential interaction . Researchers should investigate whether this relationship is altered in A. vitis, particularly in the context of plant host infection, as adaptation to the plant environment might have led to functional divergence compared to E. coli.
How does YidC contribute to membrane protein insertion during different stages of A. vitis infection?
A. vitis has a complex lifecycle involving soil survival, epiphytic colonization, and endophytic growth within grapevines . The membrane protein requirements likely differ substantially during these phases, suggesting potential temporal regulation of YidC activity.
To investigate stage-specific YidC functions, researchers could:
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Perform transcriptomic and proteomic analyses comparing YidC expression levels and interacting partners during:
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Free-living soil stages
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Initial plant colonization
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Crown gall formation
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Systemic spread through xylem
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Use conditional YidC depletion at different infection stages to identify phase-specific essential functions
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Employ ribosome profiling to identify YidC-dependent membrane proteins translated during specific infection phases
This research could reveal whether YidC is particularly important for the insertion of specific virulence factors during crown gall formation. For instance, as A. vitis produces Ti plasmid-encoded proteins essential for T-DNA transfer during infection , YidC might be critical for the insertion of membrane components of the type IV secretion system that delivers T-DNA to plant cells.
What structural and functional differences exist between A. vitis YidC and homologs in other bacterial species?
Understanding the unique characteristics of A. vitis YidC compared to well-studied homologs provides insight into potential specialized functions. Based on available information and established research approaches, the following comparative analyses would be informative:
| Feature | Analysis Method | Expected Insights |
|---|---|---|
| Primary sequence | Multiple sequence alignment | Identification of A. vitis-specific residues and domains |
| Transmembrane topology | Hydropathy analysis, reporter fusion assays | Differences in membrane integration pattern |
| Substrate specificity | In vitro insertion assays with varied substrates | Preferential insertion of plant pathogen-specific proteins |
| Interaction partners | Pull-down assays, crosslinking mass spectrometry | A. vitis-specific YidC-interacting proteins |
| Environmental sensitivity | Functional assays under varied conditions (pH, temperature) | Adaptation to plant host environments |
While E. coli YidC has been extensively characterized, A. vitis YidC may have evolved specific adaptations for its phytopathogenic lifestyle. For example, A. vitis must withstand plant defense responses and seasonal temperature fluctuations that affect crown gall disease outbreak . These environmental pressures could have selected for functional adaptations in its membrane protein insertion machinery.
What are the technical limitations in studying A. vitis YidC?
Several technical challenges currently limit comprehensive investigation of A. vitis YidC:
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Genetic manipulation complexity: Unlike the well-established E. coli system, genetic tools for precise manipulation of A. vitis are more limited, making generation of deletion mutants, conditional expression strains, and reporter fusions more challenging.
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Membrane protein solubilization: As a multi-spanning membrane protein, YidC presents inherent difficulties in extraction, purification, and structural characterization. Detergent screening is often necessary to identify conditions that maintain native conformation.
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Plant-microbe interface complexity: Studying YidC function during actual plant infection introduces variables that are difficult to control in laboratory settings, including plant defense responses and microbiome interactions.
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Functional redundancy: Potential overlapping functions with other membrane insertion pathways may mask phenotypes in single-gene manipulation studies, necessitating systems-level approaches.
Researchers can address these challenges through collaborative approaches combining expertise in membrane protein biochemistry, plant pathology, and structural biology. Development of A. vitis-specific genetic tools remains a priority for advancing this research area.
How might YidC be exploited for agricultural applications in controlling crown gall disease?
Understanding A. vitis YidC function could potentially lead to novel control strategies for crown gall disease, which remains a significant problem in vineyards worldwide . Several research directions hold promise:
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YidC as a drug target: If sufficiently different from plant homologs, compounds that specifically inhibit A. vitis YidC function could disrupt bacterial membrane protein insertion without affecting plant hosts.
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Attenuated strains as biocontrol agents: Engineering A. vitis strains with modified YidC function could potentially create non-pathogenic competitors that occupy the same ecological niche as pathogenic strains.
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Diagnostic applications: YidC-based detection methods might offer advantages for identifying A. vitis in nursery stocks, supporting the crucial disease management strategy of using healthy planting material in areas with no history of crown gall .
To evaluate these possibilities, researchers must first establish the essentiality of YidC in A. vitis and characterize its substrate specificity, particularly regarding virulence-associated membrane proteins. This fundamental knowledge will determine whether YidC represents a viable intervention point for crown gall disease management.
