The yeast-2-hybrid system is a simple scientific technique used to screen a library of proteins for potential interactions
- Firstly, a transcription factor is broken into two parts – a DNA-binding domain (BD) and a catalytic activation domain (AD)
- The DNA-binding domain is fused to a protein of interest called the bait (e.g. an enzyme)
- The activation domain is fused to a number of potential binding partners – called the prey (e.g. different ligands)
- If the bait and prey interact, the two parts of the transcription factor are reconstituted and activate transcription of a gene
- If the bait and prey do not interact, the two parts of the transcription factor remain separate and transcription doesn’t occur
The yeast-2-hybrid system detects protein-protein interactions according to the activation of a reporter gene
- The reporter gene may encode for the production of a protein that causes a visible colour change (e.g. ß-galactosidase)
- Alternatively, the reporter gene may encode for the production of an essential amino acid that is required for the yeast to grow on a deficient media (hence yeast growth would indicate successful interaction between bait and prey)
Yeast-2-hybrid screens are a simple technique and hence have a relatively high rate of false positives (partial interactions)
- Consequently, the yeast-2-hybrid system is typically only used as an initial test to identify possible protein interactions
Overview of the Yeast-2-Hybrid System
