RNA Polymerase-Associated Transcription-Specificity Factor RAP94 (RAP94) Vaccinia Virus Recombinant Protein

DNA-directed RNA polymerase-associated factor required for the transcription of viral early genes as well as for transcription termination. Within minutes after virus entry, recruits the core RNA polymerase, the early transcription factor (ETF) and other enzymes needed for transcription initiation, elongation, and termination thereby allowing synthesis of early mRNAs which are extruded through pores in the core particle. Recruits the multifunctional J3 protein, with poly(A) polymerase-stimulatory, cap nucleoside-2'-O-methyltransferase, and transcription elongation activities. Interacts with NPH-I, a DNA-dependent ATPase required for the termination of early transcripts. Acts as a transcription termination factor by binding, together with the capping enzyme/VTF, to the termination motif 5'-UUUUUNU-3' in the nascent mRNA. Involved as well in the packaging of RNA polymerase and other components needed for early transcription in assembling virus particles.