Transcription factor access is mediated by accurately positioned nucleosomes on the mouse mammary tumor virus promoter.

摘要: A fragment of the mouse mammary tumor virus (MMTV) promoter was reconstituted from pure histones into a dinucleosome with uniquely positioned octamer cores. Core boundaries for in vitro-assembled corresponded to observed vivo phasing pattern long terminal repeat nucleosomes and B. Nuclear factor 1 (NF1), constituent MMTV transcription initiation complex, excluded assembled dinucleosome, whereas glucocorticoid receptor able bind. During vivo, displacement nucleosome B necessary permit assembly complex. These results indicate that nucleoprotein structure can provide differential access sequence-specific DNA-binding proteins active chromatin remodeling occur during activation.