In contrast, cells transfected with a catalytically inactive mutant of RNaseH1 (pICE-RNaseH1-D10R, E48R-NLS) retain the ability to deacetylate H3K18 upon infection (Fig 5A), which demonstrates that only catalytically active RNaseH1 blocks H3K18 deacetylation. This evidence concerns the gene RNASEH1 and infection.