In 9 __NODE__ __NODE__ treated __SP__ , binding of __NODE__ protein and a protein fragment ( 200 462 ) containing a ligand binding domain from __SP__ __NODE__ protein is the same as binding of mutant __NODE__ protein ( L748A L749A with its NR box 3 mutated ) and a protein fragment ( 200 462 ) containing a ligand binding domain from __SP__ __NODE__ protein .