A PROTAC molecule is composed by the following moieties.

Question

The ligand of protein of interest, the linker, and the E3 ligand.
The E3 ligand, the linker, a second E3 ligand.
The ligand of the protein of interest, the linker, a second ligand of the protein of interest.
None of the above

Answer 1

A PROTAC (proteolysis-targeting chimera) molecule is typically composed of three main components:

1. Ligand for the protein of interest - This moiety binds specifically to the target protein that you want to degrade.

2. Linker - This component connects the two ligands (the ligand for the protein of interest and the E3 ligase ligand). The linker is crucial for maintaining the proper spatial orientation between the two ligands to facilitate the interactions needed for targeted degradation.

3. Ligand for an E3 ubiquitin ligase - This part binds to an E3 ligase, which is responsible for tagging the target protein for degradation via the ubiquitin-proteasome pathway.

Based on the descriptions you provided:

• "The ligand of protein of interest, the linker, and the E3 ligand" is the correct description of a PROTAC molecule.

Therefore, the answer is: The ligand of protein of interest, the linker, and the E3 ligand.