Team:Hong Kong CUHK/abstract

To rapidly regulate biological process, we designed a novel transmembrane protein called Voltage Switch (VS), which is a fusion protein utilizing the voltage sensing domain from potassium ion channels. Triggered by a change of potential across the inner membrane, VS can bring targeting enzymes into proximity, thus allowing an instant control of enzymatic reaction. We also utilized VS to accelerate the polycyclic aromatic hydrocarbons (PAHs) degradation system — another highlight of our project. The metabolites of certain PAHs are mutagenic and carcinogenic. We codon-optimized laccase from Bacillus sp. HR03 and catechol 1,2-dioxygenase from Pseudomonas putida KT2440 for Escherichia coli, which when forming a cascade, can degrade PAHs into less toxic simple carboxylic acid. For regulation, we added quinone sensing and response repressor (QsrR) to control the degradation, as quinones are intermediates in the pathway.