Better together: constructing useful artificial protein oligomers using synthetic biology

One of the most important events a protein will undergo is associating with itself or other proteins to from a functional complex; this is known as oligomerisation. Protein oligomerisation is common place in nature, with the majority of cellular proteins existing either permanently or transiently as oligomers. Oligomerisation is normally cooperative and synergistic in that properties such as function and stability are greatly enhanced compared to the monomeric form, and new properties can emerge (e.g. functional enhancement, switching); there is normally communication between individual monomer units that leads to these new or enhanced properties. Your PhD research project will involve taking normally monomeric proteins and then designing, building and testing new oligomeric protein species. While oligomerisation could be considered desirable, it is difficult to engineer into functional monomeric proteins due to the complexity of natural protein-protein interfaces. To meet this challenge, you will use a new synthetic biology approach recently developed in the Jones group for generating protein oligomers: biorthongonal Click crosslinking. You will use a reprogrammed genetic code to incorporate non-natural amino acids (nnAA) at designated residues in a target protein. At least two different types of nnAA will be used that are not found in nature but can react on a 1 to 1 basis to form a defined crosslink. Using this system, you will explore the construction of dimer, trimers and beyond composed of identical and mixed protein units to generate a myriad of new structures of potential fundamental and technological use. Your project will initially focus on autofluorescent proteins (e.g. GFP) but will quickly move on to constructing multi-enzyme complexes. This interdisciplinary project will focus on protein design and engineering but will also expose you to elements of chemistry and biophysics.