Source:http://linkedlifedata.com/resource/umls/id/C0682969
NCI: A Binding Site Domain is a region of protein that physically interacts stereospecifically, and usually at high affinity, with a specific ligand, substrate, or a specific domain of some complex target biomolecule, such as a protein, lipid, carbohydrate, or nucleic acid. Typically, but not necessarily, the interaction results in protein conformational alteration and functional modification.