Difference between revisions of "Part:BBa K1442039"

Revision as of 22:15, 16 October 2014

P2A self-cleaving peptide sequence

The self-cleaving 2A peptide (18-22 amino acids) is a virally derived coding region that has been utilised by viruses to self-cleave during translation and is likely to have arisen to overcome traditional IRES sequences due to its much smaller coding length and allows for a smaller viral genome [1].

Of the available 2A coding regions coding for the peptide from various viruses: foot-and-mouth disease virus, equine rhinitis A, Thosea asigna, porcine teschovirus-1. The porcine teschovirus 2A (P2A) had the highest efficiency of cleavage in three mammalian cell lines tested by Kim et al [1]: human, zebrafish and adult mice.

The P2A peptide can be used in a research context to allow multicistronic expression of genes without traditional methods of: multiple promoters, insertion of a splicing signal, insertion of a proteolytic cleavage site (e.g. TEV) and IRESs. Of note, P2A overcomes the limitations of an IRES: it is much smaller and also improves the translational efficiency of IRES-based genes [1]. The use of P2A is therefore useful to allow coexpression of large proteins in plasmids where the size of the insert is limiting and preserves the authenicity of a expressed protein sequence over traditionally cleaved protein in vitro such as TEV protease sites that leave a scar site.

Usage and Biology

This aptazyme was included as an RNA kill switch We put this structure centrally in our replicon in order to cause the maxmimum disruption when activated with theophylline.

Sequence and Features