Site-specific conjugation of oligonucleotides to the C-terminus of recombinant protein by expressed protein ligation

We developed a convenient method for synthesizing homogeneous DNA–protein conjugates. The method is based on expressed protein ligation of intein-fusion proteins and oligonucleotides derivatized with a cysteine. A range of cysteinyl oligonucleotides were synthesized by using a new reagent 1 and were successfully applied to expressed protein ligation to attach the oligonucleotides specifically at the C-terminus of a recombinant protein.