Binding of a protein chimera composed of a protein fragment ( 198 389 ) from __SP__ __NODE__ protein and of a mutant protein fragment ( 299 455 ) ( deletion 326 336 insertion 325 326 from a protein fragment ( 416 426 ) from __SP__ __NODE__ protein ) from __SP__ __NODE__ protein and ligand binding domain from __NODE__ protein(s) occurs in __SP__ .