Mystery of operon evolution probed Date: August 30, 2012 ... the bacterium Escherichia coli used three specialized genes to create the proteins it needed to break down and digest lactose.

I explained that when lactose is absent, a protein—the lac repressor, encoded by the lacI gene—binds to the operator, blocking RNA polymerase from transcribing the genes of the operon into ...

So Collins and his graduate student Tara Deans decided to follow the 'divide and conquer' paradigm; they combined repression at a lactose operon (lac) and a tet-controlled promoter with RNA ...