Yeast two-hybrid system allows detection of interacting proteins. In the following schematic, various components of yeast two-hybrid system have been indicated by letters A-F.

Which one of the following options provides a correct match of A to F and components of yeast two-hybrid system?

Correct option is D

The correct answer is: (4) A- Gal4 activation domain; B- Prey; C- Bait; D- Gal4 binding domain; E- UAS element; F- Reporter gene

Explanation : In the yeast two-hybrid system, the setup involves the use of a transcription factor from the yeast Gal4 protein. This transcription factor is split into two components:

• A (Gal4 activation domain): This domain is responsible for activating transcription once the appropriate interaction occurs.

• B (Prey): The Prey is the protein of interest that is being tested for interaction with the Bait.

• C (Bait): The Bait is the other protein being tested for interaction with the Prey.

• D (Gal4 binding domain): This domain binds to the UAS element and facilitates the transcription process when in close proximity to the activation domain.

• E (UAS element): This element is a DNA sequence that is recognized by the Gal4 binding domain, leading to transcription activation.

• F (Reporter gene): The expression of the Reporter gene depends on the activation of transcription, which is triggered by the interaction between Prey and Bait, facilitated by the Gal4 domains.

Thus, the components and their correct relationships align with the yeast two-hybrid system as shown in option 4.

Information Booster:

1. The Gal4 activation domain (A) is responsible for initiating transcription when it is brought into proximity with the Gal4 binding domain (D).

2. The Bait (B) and Prey (C) represent the two proteins whose interactions are being tested.

3. Gal4 binding domain (D) binds to the UAS element (E), a DNA sequence that drives the expression of the Reporter gene (F).

4. The Reporter gene is activated only if Bait and Prey interact, confirming a positive interaction.

5. The yeast two-hybrid system is a powerful tool for identifying protein-protein interactions in vivo, particularly in yeast cells.

6. The system is typically used to study protein interactions at a molecular level and can be applied to various types of protein function analysis.

Additional Information:

• Option 1: The Gal4 activation domain should not be paired with Prey or Bait because it is responsible for transcription activation.

• Option 2: The Gal4 binding domain should not be incorrectly assigned to the Prey and Bait proteins.

• Option 3: The Gal4 activation domain is mistakenly assigned to the wrong components, leading to incorrect interactions in the system.