Rpn4p is a transcription factor responsible for coordinated regulation of proteasomal genes in Saccharomyces cerevisiae. There are data suggesting an involvement of this factor in regulation of many other genes that comprise more than one tenth part of the yeast genome. Traditional methods are inapplicable for mapping of Rpn4p binding sites because of their extremely low level. We have developed a model system using Dam-methylase of E. coli which allows us to detect interaction of Rpn4p with its target genes. In this system, we have shown that Rpn4p is recruited to proteasomal genes only through interactions with DNA.