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 greater than binding of mutant __NODE__ protein ( L693A L694A with its NR box 2 mutated ) and a protein fragment ( 200 462 ) containing a ligand binding domain from __SP__ __NODE__ protein .