In a system of purified components , the affinity of binding of __SP__ __NODE__ protein and __SP__ __NODE__ protein containing a carboxy terminal domain and a linker domain and a N terminal domain is greater than the affinity of binding of a protein chimera composed of a protein fragment ( 1 89 ) containing a N terminal domain from __SP__ __NODE__ protein and of a protein fragment ( 82 270 ) containing a carboxy terminal domain and a linker domain from __SP__ __NODE__ protein and __SP__ __NODE__ protein .