A Cellular Factor Binds to the Herpes Simplex Virus Type 1 Transactivator Vmw65 and Is Required for Vmw65-Dependent Protein-DNA Complex Assembly with Oct-1

The herpes simplex virus transactivator Vmw65 assembles into a multicomponent protein-DNA complex along with the octamer binding protein Oct-1. Using affinity chromatography on columns conjugated with purified Vmw65 fusion protein expressed in Escherichia coli, we demonstrate that a cellular factor, distinct from Oct-1, binds to Vmw65 in the absence of target DNA and is necessary for Vmw65-mediated complex assembly with Oct-1.