| When the MMTV retrovirus integrates into host cell DNA as a provirus,
the LTR (containing transcriptional regulatory sequences)
is organized into a reproducible chromatin structure. |
|
 |
| This structure is characterized at low resolution
by a series of positioned, or “phased” nucleosomes. |
|
 | When replicated in mammalian cells, this promoter acquires a specific
nucleoprotein organization. |
| Steroid receptors bind to the B/C nucleosome region and activate transcription. |
|
| An important component of this activation mechanism is a
nucleoprotein remodeling event (in the B nuclesome region)
that leads to loss of chromatin repression. |
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