Affinity chromatographic purification of a protein which binds specifically to the yeast leucine tRNA gene.

A crude cell extract from yeast Saccharomyces cerevisae was fractionated by affinity chromatography using the leucine tRNA gene as the recognition site. This approach enables the rapid purification of a protein, which retained its full DNA binding capacity during the enrichment procedure. The active fraction contains two major polypeptides of 140 and 170 kDa and a minor component of 100 kDa. The 170-kDa component does not bind to the DNA. The likelihood that the DNA binding protein is one of the components of transcription factor tau is discussed.