Acts with RNA polymerase to initiate transcription from early gene promoters. A DNA-dependent ATPase activity is associated with VETF. Heterodimer of a 70 kDa and a 82 kDa subunit. All the enzymes and other proteins required to synthesize early mRNAs are packaged within the virion core along with the DNA genome. This is necessary because viral early mRNAs are synthesized within minutes after virus entry into the cell and are extruded through pores in the core particle. Belongs to the helicase family. VETF subfamily.