Part:BBa_K3718000

Our Modular Receptor Platform (MRP) is designed according to the paper published in 2017 (Chang et al.). The modular biosensor is composed of the E. coil CadC DNA binding domain, a juxtamembrane bridge region, an artificial 16-Leucine transmembrane region and a transmembrane receptor with customizable VHH region, which is a restriction site.

When the nanobody binds the target, dimerization of the protein CadC domains occur. As a result, this allows the binding of the pCadBA operon region and transcription downstream is promoted at the same time.

Customizable VHH region

The VHH region has high flexible posibilities as it can be customized for binding with different targets, so that any specific targets with single-domain antibodies available are potentially ligand candidates for this receptor.

Users can add their own antibody VHH region after the transmembrane region DNA via restriction ligation. The KasI restriction site, together with sequence GCC, is added at the C-terminus of the transmembrane region. The addition of the restriction site is 3 bp. Therefore, the coding region, which includes the user’s VHH, is in-frame. A minimum addition of nucleotides is added in order to reduce any effect of the additional codon to the coding region. At the same time, KasI recognizes a 6bp site, so that the chances of having the cut site in other regions of the user's DNA are relatively low.