Binding of a protein fragment ( 613 752 ) containing a LXXLL motif 1 ( aa sequence LLQLL ) and a LXXLL motif 2 ( aa sequence LHKLL ) and a LXXLL motif 3 ( aa sequence LRYLL ) and a receptor binding domain from __NODE__ protein and mutant __NODE__ protein ( V298A L301A ) occurs in a cell free system .