In a cell free system , binding of promoter fragment containing a __NODE__ binding site ( 5 ' TGTTTCA 3 ' and a __NODE__ response element ( 5 ' GGAAAA 3 ' from __SP__ __NODE__ gene and heterodimer consisting of __NODE__ and of __NODE__ is greater than binding of promoter fragment containing a __NODE__ binding site ( 5 ' TGTTTCA 3 ' and a __NODE__ response element ( 5 ' GGAAAA 3 ' from mutant __SP__ __NODE__ gene ( G?C A?T G?C G?C A?T with its __NODE__ response element mutated ) and heterodimer consisting of __NODE__ and of __NODE__ .