Part:BBa_K627006

Fusion part of mdnA gene (from mdn-cluster) with myc-tag and gene III

The following BioBrick is important for testing the suitability of a phage display system as an appropriate screening methoe for recombinant mdnA libraries.
mdnA gene encodes the precursor peptide from the mdn-cluster, which is an essential building block for production of the protease inhibitor microviridin from Microcystis aeruginosa (Ziemert et al., 2008). This gene is known to be able to bind and inhibit proteases. Thus they have a high potential for therapy as they can block disease-relevant proteases (Ziemert et al., 2008 and 2010).
The gene III protein is a coat protein from the filamentous bacteriophage M13. It appears only three to five times on the tip of the phage and is responsible for infection of bacterial cells. In phage display, genes from a DNA library are usually fused to the gene III and are displayed as fusion protein on the surface of the phages. Because it has been shown that the proteins of interest, which are fused to the c-terminus of gene-III can be functionally displayed only the sequence for this part has to be used.
The inserted sequence of the myc-tag enables the easy way for detection or purification of the proteins of interest.
After transformation of E. coli with a vector containing the mdnA-myc-geneIII-fusion gene and co-infection with helper phages E. coli cells were able to produce phage particles, which carry the microviridin peptide on their surface. This was confirmed by ELISA test. Using these phages the fundamental suitability of phage display as a screening method for varieties was pointed.