A Salmonella virulence operon has three genes that are impor

A Salmonella virulence operon has three genes that are important for invasion of host cells. These proteins are not produced when the bacteria are growing outside of the host, and are only produced when the bacteria are growing inside the host. Based on this information, how many promoters are there, and what is the mode of regulation? 3; inducible 1;inducible 3;repressible 1;repressible

Solution

Since it is given as operon, which means a set of proteins that are controlled by a single promoter, we can relate to 1 promoter. Whether it is inducible or repessible? Host is inducing the activation of promoter. Some of the host proteins might be acting as inducers.

Therefore, it may be 1, inducible