title: The invariably present tryptophan loop as the core of all divergent antigen-binding pockets.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000916:Antibody Diversity; D001666:Binding Sites, Antibody; D006801:Humans; D007143:Immunoglobulin Heavy Chains; D007147:Immunoglobulin Light Chains; D007135:Immunoglobulin Variable Region; D051379:Mice; D011487:Protein Conformation; D011948:Receptors, Antigen, T-Cell; D014364:Tryptophan
chemical_list: D007143:Immunoglobulin Heavy Chains; D007147:Immunoglobulin Light Chains; D007135:Immunoglobulin Variable Region; D011948:Receptors, Antigen, T-Cell; D014364:Tryptophan