A region on a protein other than its active site (q.v.), to which a specific effector molecule may bind and influence (either positively or negatively) the functional activity of the protein. For example, in the lactose system of E. coli, the lac repressor becomes inactive (cannot bind to the lac operator) when allolactose is bound to the allosteric site of the repressor molecule. See lac operon.
Subjects: Genetics and Genomics.