In a cell free system , binding of a mutant DNA fragment ( C 113G A 106C ) containing a __NODE__ response element from __SP__ __NODE__ gene and __SP__ __NODE__ protein is the same as binding of a mutant DNA fragment ( A 111C A 110C C 109G T 108G ) containing a __NODE__ response element from __SP__ __NODE__ gene and __SP__ __NODE__ protein .