The high-mobility group (HMG) proteins 14 and 17 are abundant chromosomal proteins that bind to nucleosomes and enhance transcription (1–5). HMG-14 and HMG-17 also function as architectural elements, which alter the structure of the chromatin fiber and enhance transcription from chromatin templates (1–3,5). HMG-14/17 proteins modify the nucleosomal organization of the 30 nm chromatin fiber and mediate the unfolding of the higher order chromatin structure thereby facilitating access to th