A simple and efficient method for the purification of specific DNA binding proteins

In an attempt to purify large amounts of a protein that specifically binds to a newly identified UV-responsive element (URE) we have developed a simple method that enables efficient coupling of specific target DNA sequences to a support matrix. Although several procedures have been report, the efficiency of coupling the target DNA sequence to the support matrix is routinely low or the procedures are highly specialized and labor intensive to perform. In the newly developed procedure, the DNA sequence of interest is initially tailed with poly(A) nucleotides and subsequently coupled to oligo-dT cellulose. The affinity columns prepared in this way are quick and simple to construct and the attachment of the DNA to the column occurs at the ends of the oligomer rendering the entire target sequence available for protein binding.