Question

Which of the following statements is NOT true regarding a yeast two-hybrid system?

A: This technique can investigate whether proteins will interact with one another.
B: A functional transcription factor is created when two different proteins interact with one another and activate a reporter gene.
C: The activity of a reporter gene can be used to monitor the presence of an active transcription factor.
D: Either hybrid protein produced in this system can activate the reporter gene, but if the proteins interact, the reporter gene is turned off.
E: Large numbers of proteins can be screened using this system.

Answer 1

The incorrect statement regarding a yeast two-hybrid system is that 'Either hybrid protein produced in this system can activate the reporter gene, but if the proteins interact, the reporter gene is turned off.' The system actually works by activating the reporter gene when the bait and prey proteins interact.

Step-by-step explanation:

The statement that is NOT true regarding a yeast two-hybrid system is: D: Either hybrid protein produced in this system can activate the reporter gene, but if the proteins interact, the reporter gene is turned off. In actuality, the opposite is true in a yeast two-hybrid system. The method is designed to detect protein-protein interactions where the reporter gene is only activated when the two proteins of interest, the bait and the prey, interact.

The yeast two-hybrid system involves splitting a transcription factor into two separate domains: the DNA-binding domain (BD) and the activator domain (AD). The bait protein is fused to the BD and the prey protein is fused to the AD. If the bait protein interacts with the prey protein, the transcription factor's domains come together, and the reporter gene is activated, allowing for the detection of the interaction.

Therefore, the activation of the reporter gene indicates a successful interaction, or, as stated, transcription occurs when the prey 'catches' the bait. If the prey doesn't catch the bait, meaning the proteins do not interact, no transcription occurs and the reporter gene remains inactive. This system allows for