This study investigated the structure of the Max:DNA complex by cross-linking Max to photoactive oligonucleotides containing an aryl azide group downstream from the specific CACGTG binding site. Max homodimers were found to cross-link to oligonucleotides with the photoactive group 2, 5, 8, or 11 base pairs downstream. Further analysis revealed that an amino-terminal peptide of Max was cross-linked to the oligonucleotide containing the photoactive probe 11 base pairs downstream, consistent with the known crystal structure.