Figure 4.

Addressing specificity of M·HhaI, M·MspI, and M·HhaI-dod fusion protein. Oligodeoxynucleotide sequences carrying the centrally located recognition sequence for M·MspI (Left) or M·HhaI (Right) were synthesized with 5-fluorocytosine substituted for cytosine at the target site. After electrophoresis through polyacrylamide gel, ³²P-end-labeled DNAs in complexes were visualized by autoradiography. ³²P-end-labeled retardation products are formed only between an enzyme and its homologous recognition site. Cross-reactivity was not observed. This was not only true of the native enzymes but it was also true of the chimeric protein containing the dodecapeptide extension at its C terminus.