In a cell free system , binding of promoter fragment ( 83 36 ) from __SP__ __NODE__ gene and heterodimer consisting of __SP__ __NODE__ and of __SP__ __NODE__ is greater than binding of promoter fragment ( 83 36 ) from mutant __SP__ __NODE__ gene ( deletion 52 36 ) and heterodimer consisting of __SP__ __NODE__ and of __SP__ __NODE__ .