Abstract: While allostery has been a topic of intense interest for the past several decades, our understanding of the underlying mechanism at the molecular level continues to be challenged by new experimental observations. Specifically, a recent deep mutational scanning study of a bacterial transcription factor TetR found that allostery hotspot residues are broadly distributed over a major portion of the protein structure, rather than being clustered near the ligand-binding and DNA-binding domain interfaces as often discussed in structure-based studies.