Question

Explain what is meant by the term “allostery” and give two examples explaining how this can influence regulation of a gene

Answer 1

Allostery is a process of regulation of enzyme.For allosteric enzyme has two site one is active site and other is allosteric site.Effector molecule will act on this allosteric site and regulate the conformation of active site of an enzyme or protein(may be transcription factor).

Example:

Aspartate carbamoyl transferase one the example for allosteric regulation of gene.it is the enzyme for synthesis of pyrimidine,and also regulate purine, pyrimidine and arginine biosynthesis. This enzyme will inactive in presence of CTP and UTP. But it will be active in presence of ATP.

Another one is yeast chorismate mutase, which allosteric regulated protein. It is enzyme for biosynthesis of aromatic amino.Activation of enzyme by tryptophan(R state) and inactivation by tyrosine (T state).