In biochemistry, a binding site is a region of a protein, DNA or RNA in which another specific molecule or ion forms a chemical bond.
The term saturation refers to the fraction of the total binding centers that are occupied (they have a molecule or ion attached to it) at a given time. When more than one type of ligand can bind to a binding site, competition occurs between them. There is a balance between bound and unbound ligands to the binding centers. The binding sites also exhibit chemical specificity (the measure of the types of ligands that can bind to the center), and chemical affinity (the measure of the strength of chemical bonds). A more specific type of binding site is the binding site of the transcription factor present in DNA.
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