Replication of a chimeric origin containing elements from Epstein-Barr virus ori P and bovine papillomavirus minimal origin

The bovine papillomavirus E2 protein is a multifunctional protein that acti vates viral transcription, co-operates in initiation of viral DNA replicati on, and is required for long-term episomal maintenance of viral genomes. Th e EBNA1 protein of Epstein-Barr virus is required for synthesis and mainten ance of Epstein-Barr virus genomes. Both viral proteins act through direct interactions with their respective DNA sequences in their origins of replic ation. The chimeric protein E2:EBNA1, which consists of an transactivation domain of E2 and DNA binding domain of EBNA1 supported the replication of t he chimeric origin that contained EBNA1 binding sites in place of the E2 bi nding sites principally as full-length E2 did in the case of papillomavirus minimal origin. This indicates that the chimeric protein E2:EBNA1 is compe tent to assemble a replication complex similar to the E2 protein. These dat a confirm the earlier observations that the only part of E2 specifically re quired for its activity in replication is the N-terminal activation domain and the function of the DNA binding domain of E2 in the initiation of repli cation is to tether the transactivation domain of E2 to the origin of repli cation. (C) 2001 Elsevier Science B.V. All rights reserved.