paratope

thumb| An antibody with a circled region depicting where the paratope is found. 1. Fragment antigen-binding|Antigen-binding fragment (Fab) 2. Antibody crystallizable region (Fc) 3. Heavy chains 4. Light chains 5. Variable region of the antibody. The paratope is the key-shaped section that makes direct contact with the [[antigen. 6. Hinge regions ]]

In immunology, a paratope, also known as an antigen-binding site, is the part of an antibody which recognizes and binds to an antigen. It is a small region at the tip of the antibody's antigen-binding fragment and contains parts of the antibody's heavy and light chains. Each paratope is made up of six complementarity-determining regions - three from each of the light and heavy chains - that extend from a fold of anti-parallel beta sheets. Each arm of the Y-shaped antibody has an identical paratope at the end.