https://doi.org/10.1351/goldbook.B00649
A specific region (or atom) in a @M03986@ that is capable of entering into a stabilizing interaction with another molecular entity. An example of such an interaction is that of an active site in an enzyme with its @S06083@. Typical forms of interaction are by @H02899@, @C01329@ and @I03231@ formation. Two binding sites in different molecular entities are said to be complementary if their interaction is stabilizing.