Recombinant Escherichia coli O7:K1 Peptide chain release factor 1 (prfA)
Description
Molecular Function and Genetic Context
PrfA (encoded by the prfA gene) is a class 1 release factor that facilitates ribosomal recognition of termination codons and catalyzes the hydrolysis of peptidyl-tRNA bonds . Key features include:
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Structural Homology: Shares high sequence similarity with RF2 (PrfB), including conserved motifs critical for codon recognition and ribosome interaction .
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Regulatory Mechanism: The prfA gene contains an in-frame premature UGA codon, requiring a ribosomal frameshift for full-length protein synthesis, suggesting translational control .
Recombinant Production and Biochemical Properties
Recombinant PrfA is engineered for studies on translation termination and antimicrobial applications.
Table 1: Key Biochemical Properties of Recombinant PrfA
| Property | Details | Source |
|---|---|---|
| Expression System | E. coli O7:K1 | |
| Purity | >85% (SDS-PAGE) | |
| Storage Buffer | Tris-based buffer with 50% glycerol | |
| Applications | Western blotting, ELISA, functional assays |
Role in Bacterial Virulence and Therapeutic Potential
While PrfA itself is not a virulence factor, its host E. coli O7:K1 is associated with pathogenicity due to the K1 capsule, a polysaccharide critical for immune evasion .
Table 2: Functional Synergy Between K1 Capsule and PrfA
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K1 Capsule: Enhances survival in human serum across diverse E. coli lineages, including O7:K1 .
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PrfA in Pathogenesis: Mutations in prfA may indirectly affect bacterial fitness during infection by altering stress response pathways .
Evolutionary and Phylogenetic Insights
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K1 Capsule Prevalence: Found in 25% of bloodstream infection isolates, acquired independently in four E. coli phylogroups over 500 years .
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PrfA Conservation: The prfA gene is highly conserved across E. coli strains, including O7:K1, underscoring its essential role in translation .
Challenges and Future Directions
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Antimicrobial Strategies: Phage-derived enzymes (e.g., K1F) and capsule-targeting therapies show promise against K1-positive E. coli, but PrfA-specific inhibitors remain underexplored .
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Recombinant Protein Limitations: Current PrfA production systems face challenges in yield and stability, necessitating optimized expression protocols .
Product Specs
Target Background
KEGG: ect:ECIAI39_1547
