Putative viral E3 ligase that plays an essential regulatory role in both viral DNA replication and transcriptional transactivation. The role in transcription has been shown to include activation of gene expression from early viral promoters. Promotes also the efficient egress of nucleocapsids from the host nucleus. May act as an E3 ligase that promotes ubiquitination of nucleocapsids proteins by vUbi and subsequent viral egress for the host nucleus. Interacts with proteins C42 and FP25. Interacts with host beta-tubulin. Interacts with Ac66 and vUb.