In a cell free system , binding of __NODE__ __NODE__ response element and a protein fragment ( 1086 1449 ) from __SP__ __NODE__ protein and a heterodimeric protein protein complex consisting of __NODE__ and of __SP__ __NODE__ is greater than binding of __NODE__ __NODE__ response element and a protein fragment ( 1086 1449 ) from __SP__ __NODE__ protein and a heterodimeric protein protein complex consisting of __NODE__ and of mutant __SP__ __NODE__ ( M259I ) .