In a cell free system , binding of a DNA fragment containing a RARE from __SP__ Laminin b1 gene(s) and heterodimer consisting of __NODE__ and of __NODE__ is greater than or equal to binding of a DNA fragment containing a RARE from __SP__ Laminin b1 gene(s) and heterodimer consisting of mutant __NODE__ ( C terminal truncation 383 End with its activation domain and its dimerization domain mutated ) and of __NODE__ .