A 2A peptide sequence is a coding sequence for a polypeptide that has cytosine deaminase activity. A heterologous polynucleotide encoding the desired polypeptide is operably linked to the coding sequence.
Various eukaryotic viruses encode 2A peptides. Among these are foot-and-mouth disease virus, encephalomyocarditis virus, and Thosea asigna virus. The peptides are typically 16-18 amino acids long, and share a consensus motif. These peptides have been used as molecular tools for multiple-protein expression. However, the specific features of 2A peptides have raised questions regarding their native function and their utility in therapeutic applications.
In general, a 2A peptide is a small peptide that interrupts translation. This can lead to ribosome failure at the peptide bond. It can also serve as a tool for stable gene co-expression. As such, it has been tested in many eukaryotic cells. Moreover, mutations of the peptide can improve its expression and stability in the host cell.
The peptide can be introduced into an R-peptide or added after it. During this process, the C-terminus of the peptide can be removed from the R-peptide. Alternatively, the peptide can be cleaved. This will lead to the release of the first polypeptide from the translational complex.
Another potential use of the 2A peptide is as a recombinant virus. Typically, a recombinant virus is produced by introducing the coding sequence of the recombinant 2A peptide into the cellular DNA of a viral vector. When this is accomplished, the resulting virus can be regenerated from the original vector.