How do bacteria avoid wasteful production of unnecessary proteins when their genes are always on? The answer lies in regulating the operon. As trp levels increase, trp binds to trpR, causing a ...

When glucose and lactose are both available, allolactose releases LacI from the operator, allowing binding of the RNA polymerase. However, in the absence of cAMP to permit CRP binding, the polymerase ...

For an E. coli bacterium, 300 is its lucky number. That’s about how many protein molecules it takes to make a life-changing shift in its diet preference, according to new research. But this shift ...