Question

Which of the following statements about mediators is incorrect?

1. The mediator can contain repressor subunits that block transcription.

2. The mediator complex connects upstream TFs to the PIC (Pre Initiation Complex).

3. The coactivator complex and mediator can work in tandem.

4. The mediator cannot replace the coactivator.

5. The mediator complex connects downstream TFs to the PIC (Pre Initiation Complex).

Answer 1

Answer- 5. The mediator complex connects downstream TFs to the PIC (pre initiation complex)

Explanation- mediators are the large complex required for organization of RNA polymerase and preinitiation complex during transcription. This mediator complex binds at engender region through transcription factors and binds at promoter through pre initiation complex and these two regions are present upstream in the gene. The enhancer is present upstream to the promoter and So that the mediator complex connects upstream TFs to the PIC.

correct statements-

1. The mediator can contain repressor subunits that blocks transcription- mediator acts as co-repressor that can silence gene expression.

2. The mediator complex connects upstream TFs to the PIC (pre- initiation complex) - the mediator complex connects upstream TFs to the PIC at the downstream.

3. The co-activator complex and mediator can work in tandem- the co-activators are factors that is required to responce of activators and bridging of DNA with RNA polymerase. These works with mediators or mediators are known as co-activators.

4. Mediators can not replace co-activators- both can work in tandem but mediator can not replace co-activators.