By cycling between phosphorylated states, VS-localized P6.9 may act as a molecular switch coordinating viral DNA packaging efficiency with late gene expression timing. (d) Given that viral nucleocapsids exclusively package non-phosphorylated P6.9, this protein must ultimately undergo complete dephosphorylation, then binds/compacts the viral genomic DNA, and completes the encapsidation process for the infection cycle [20]. This evidence concerns the gene ICA1 and infection.