Question: A quorum sensing response in a hypothetical organism (let’s call it Vibrio imaginarium) results in upregulation of one gene (qsg1) and downregulation of another (qsg2). Assume that preliminary experiments have been performed and these experiments have shown that homoserine lactone functions as the autoinducer. You are interested in how the quorum sensing response is regulated in this organism and you have isolated a mutant strain that is no longer able to upregulate qsg1 and downregulate qsg2 when treated with homoserine lactone. You find that this mutant strain fails to produce a single protein that is present in the wildtype strain due to a frameshift mutation within a particular gene (qsg3). Based on the various mechanisms of gene regulation discussed in class, propose a mechanism for how qsg1 and qsg2 expression is regulated. Describe at the molecular level all elements and allosteric interactions that your proposed mechanism requires. Your answer should be detailed but concise.
