Figure 1.

Silencing complex bound to unintegrated MLV DNA. The various proteins implicated in silencing incoming unintegrated DNA of the Moloney murine leukemia virus are depicted here. NP220 is bound directly to specific sequence elements on the viral DNA, and acts as a tether to bring histone deacetylases (HDACs) to remove acetyl groups from nearby histone tails, and to bring the trimeric HUSH complex through interactions with the MPP8 subunit. This in turn brings the SETDB1 histone methyltransferase to add the H3K9me3 mark to the H3 histone tails. MPP8 further binds the complex to the DNA by its interaction with the H3K9me3 mark. From [62].