Human cytomegalovirus UL34 binds to multiple sites within the viral genome.

The human cytomegalovirus UL34 gene encodes a sequence-specific DNA binding protein that downregulates expression of the viral immune evasion gene US3. Analysis of the viral genome identified 14 potential UL34 binding sites. Using mobility shift experiments, UL34 bound to all predicted sites that were assayed (7 of 14). Furthermore, the UL34 binding site present within the regulatory region of the US9 gene downregulates expression in a manner similar to that seen for the US3 gene.