In the field of molecular biology and biochemical research, the interaction between the BirA enzyme and specific peptide sequences has become a gold standard for site-specific labeling. As a researcher who frequently engages with high-precision protein modification tools, I have found that mastering the nuances of the BirA peptide systems—specifically those utilizing the AviTag—is essential for achieving consistent, reliable results in *in vitro* applications.
The Nature o Recombinant E. coli BirA protein (Active) (His-DDDDK tag f the BirA Enzyme
The BirA biotin-protein ligase is a fascinating 35 kDa bacterial protein derived from *Escherichia coli*. My experience with this enzyme confirms that it is a bifunctional protein of remarkable utility. It acts both as a biotin--[acetyl-CoA-carboxylase] ligase and a biotin-operon repressor. This dual functionality is encoded by the *birA* gene, which regulates biotin synthesis while simultaneously performing the critical task of post-translational modification.
When working with purified His6-BirA, I have observed that the enzyme exhibits biotin ligase activity with high specificity. It functions by activating biotin in the presence of ATP to form a biotinyl-5'-adenylate intermediate, which is then transferred to a specific lysine residue within a defined acceptor peptide sequence.
The Role of the AviTag Peptide
The most common application involves the AviTag, a 15-amino acid sequence that serves as the target for the BirA enzyme. Through my own laboratory practices, I have noted that the BirA is able to link biotin to the lysine residue of the Avi tag with exceptional efficiency.
This process is often facilitated by BirA biotin-protein ligase kits, which provide the necessary buffers and optimized concentrations to ensure the reaction proceeds to completion. Whether you are performing site-specific attachment to recombinant proteins or utilizing a BirA* enzyme (a mutant form often used for proximity labeling), the precision of thi Site specific Biotinylation by BirA - Wikis - EPFL s system is unmatched.
Practical Considerations for Research
For those looking to integrate this into their workflows, here are several key takeaways based on technical data and personal observations:
* Enzymatic Specificity: Biotinylation is mediated by the enzyme BirA biotin ligase, which recognizes the specific motif rather than the entire protein structure. This minimizes the risk of off-target labeling.
* Experimental Efficie Biotin-Protein Ligase - BIRA ncy: When using Active Recombinant E. coli BirA protein, I recommend strictly adhering to temperature and incubation time protocols. In my experience, even minor deviations in the buffer composition can affect the kinetics of the reaction.
* System Versatility: Because BirA is a biotin ligase from Escherichia coli, it is highly robust Active Recombinant E. coli BirA protein (Active) is an Escherichia coli Full length protein 2 to 321 aa range, >=65% purity and validated in WB, FuncS, in various buffer systems. However, always ensure your target protein is cor by C Huang · 2010 · Cited by 17 — Protein-protein interactions contribute to a variety of biological processes, including signal transduction, tissue integrity, and force generation (1,2). rectly folded to expose the AviTag sequence.
* Troubleshooting: If you are seeking tips for using pMal-T-Avi-His/BirA, ensure that your expression system is well-calibrated. Using the right bacterial strain, such as those optimized for protein solubi Enzymatic Biotinylation and BirA lity, can significantly improve the yield of your biotinylated product.
Conclusion
The Biotin-protein ligase system represents a cornerstone of modern biotechnology. By understanding that Biotin ligase (BirA) acts with such distinct biochemical precision, researchers can reliably modify proteins for a variety of analytical tasks. Whether you are using a commercial BirA Biotin-protein ligase kit or purifying your own enzyme, the ability to use to label the AviTag target remains one of the most effective methods for site-specific protein engineering. Having navigated these protocols multiple times, I can attest that the stability and specificity of the B p06709 · bira_ecoli irA system make it an indispensable tool for those requiring high-quality, labeled peptide constructs.