SUBNUCLEOSOME PARTICLES CONTAINING HIGH MOBILITY GROUP PROTEINS HMG-E AND HMG-G ORIGINATE FROM TRANSCRIPTIONALLY ACTIVE CHROMATIN

Subnucleosome particles SN2 and SN3 containing short DNA fragments and non-histone proteins of the high mobility group, HMG-G and HMG-B respectively, were purified from the chromatin preparations of mouse L cells partially digested with staphy-lococcal nuclease. Labeled DNAs prepared from these particles were hybridized to an excess of nuclear RNA. The binding of subnucleosomal MA was about 3-fold higher comparing to total cellular DNA fragmented to the same size. Special control experiments showed that DNA.-protein complexes present in sub-nucleosomes SN2 and SN3 preexisted in nontreated nuclei. The conclusion has been drawn that non-histone proteins HMG-G and HMG-E are associated with the DNA of transcriptionally active chromatin and are released by nuclease as subnucleosomes. © 1979 Information Retrieval Limited.