In a cell free system , binding of a DNA fragment ( GGAAAAGTGTGTCACTGGGGCACGA ) containing a Rev DR2 element from __SP__ Rev Erb alpha [__NODE__] gene and heterodimer consisting of __SP__ __NODE__ and of __NODE__ is greater than binding of a DNA fragment containing a DR1 response element from __SP__ __NODE__ gene and heterodimer consisting of __SP__ __NODE__ and of __NODE__ .