Metal Sensing

Introduction

If our project is to process cadmium and not other metals, we need to genetically engineer Bacillus subtilis to carry out a set of cellular processes based on the action of metal sensors. These metal sensors will detect cadmium through a system known as AND Gating.

There are two metal sensing repressors, which are known to respond to cadmium: arsR and czrA. By placing binding sites to these two metal sensing repressors next to each other in a promoter region, the gene regulated by that promoter will be synthesized only when a combination of metals that bind to both sensors are present; this is a combinatorial approach for gene expression regulation.