In a system of purified components , binding of __NODE__ protein and mutant __SP__ __NODE__ protein ( N terminal truncation 1 186 with its AF 1 domain deleted and with its AF 2 transcription activation domain and its hinge domain retained ) is greater than binding of __NODE__ protein and mutant __SP__ __NODE__ protein ( N terminal truncation 1 227 with its AF 1 domain and its DNA binding domain deleted and with its AF 2 transcription activation domain and its hinge domain retained ) .