In a membrane fraction from 293 cells , the affinity of binding of ( 6R ) 5 methyltetrahydrofolate and a protein chimera composed of a protein fragment ( 1 38 ) from __SP__ __NODE__ protein and of a protein fragment ( 53 59 ) from __SP__ __NODE__ protein and of a protein fragment ( 54 232 ) from __SP__ __NODE__ protein is greater than the affinity of binding of ( 6S ) 5 methyltetrahydrofolate and a protein chimera composed of a protein fragment ( 1 38 ) from __SP__ __NODE__ protein and of a protein fragment ( 39 53 ) from __SP__ __NODE__ protein and of a protein fragment ( 54 232 ) from __SP__ __NODE__ protein .