Skip to content
Login Register

#Yeast Two-Hybrid

6 public questions tagged with this topic.

Protein-Protein Interaction

If the bait and prey interact, which component is activated?

The readout of yeast two-hybrid depends on reconstitution of a functional transcription factor at the reporter locus. Bait-DNA-binding domain fusion and prey-activation domain fusion individually cannot activate transcription. Interaction bridges them, positioning the activation domain at upstream activating sequences of reporter genes such as HIS3, ADE2, or lacZ. This triggers recruitment of Mediator and RNA polymerase II, leading to measurable transcription. Reporter activation therefore serves as indirect but powerful evidence of protein-protein association inside living yeast nuclei under physiological conditions.

Ref: NCERT Biology Class XII Principles on Klenow fill-in labeling, Lehninger Chapter 9 DNA cloning techniques, and Molecular Cloning by Sambrook Chapter 10 documenting end-labeling of cohesive termini.

View Details
Protein-Protein Interaction

The 'prey' in yeast two-hybrid is fused to:

In yeast two-hybrid, functionality is split between two fusion proteins. Bait carrying the DNA-binding domain occupies promoter elements but lacks activation capacity. Prey consists of library proteins fused to a transcriptional activation domain that can recruit RNA polymerase II machinery and coactivators. Only upon physical binding between bait and prey does the activation domain localize to the reporter promoter, restoring a complete transcription factor. This design allows nuclear interaction to be converted into selectable reporter expression, forming basis for high-throughput binary interactome screening.

Ref: NCERT Biology Class XII Principles on Klenow fill-in labeling, Lehninger Chapter 9 DNA cloning techniques, and Molecular Cloning by Sambrook Chapter 10 documenting end-labeling of cohesive termini.

View Details
Protein-Protein Interaction

In a Yeast Two-Hybrid system, the 'bait' is fused to:

Yeast two-hybrid exploits the modular architecture of eukaryotic transcription factors, typically Gal4, which has separable DNA-binding and activation functions. Bait, the known protein, is fused to the DNA-binding domain to tether it to the upstream activating sequence of reporter genes. This fusion alone cannot activate transcription. When prey fused to activation domain interacts with bait, the two domains are brought into proximity, reconstituting a functional activator that drives transcription of auxotrophic or colorimetric reporters, enabling detection of interaction in vivo.

Ref: NCERT Biology Class XII Principles on Klenow fill-in labeling, Lehninger Chapter 9 DNA cloning techniques, and Molecular Cloning by Sambrook Chapter 10 documenting end-labeling of cohesive termini.

View Details