Emerging evidence shows that a module swapping strategy can be applied to many families of allosterically regulated transcriptional regulators. Regulators within each family contain conserved DNA-binding modules (DBMs) and ligand-binding modules (LBMs); a DBM binds to a specific sequence of DNA and a LBM controls DNA-binding affinity of the regulator in response to a specific ligand or enviornmental signal. The work from our group, as well as other researchers, have demonstrated that combining DBMs and LBMs originated from different family members can create hybrid regulators with new combinations of DNA recognition and allosteric response. This strategy is a powerful approach to build genetic sensors that enable flexible connections between environmental signals and genetic elements, which were harnessed to implement novel topologies of genetic circuit. However, module-module interactions can be disrupted between some DBMs and LBMs, which leads to poor functionity in resulting hybrid proteins. This limitation obstructs the use of the module swappaing strategy for many biotechnology applications.<br/>In our recent studies, we established a design strategy for restoring critical interactions between these incompatible modules based on coevolutionary traits among family members. We then used our strategy to predict mutations for reinstalling relevant module-module interactions, aiming to rescue hybrid regulators with low performance. Indeed, experimental results confirm that these mutations significantly improve the dynamic ranges of expression induction in resulting mutants. Through our studies, we also further understand the molecular mechanism of these proteins. The significance of these hybrid regulators is demonstrated with several genetic devices that we recently created.

Robust design of modular transcriptional regulators: New tools for building genetic devices

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.