DOMAINS OF THE BPV-1 E1 REPLICATION PROTEIN REQUIRED FOR ORIGIN-SPECIFIC DNA-BINDING AND INTERACTION WITH THE E2 TRANSACTIVATOR

The viral E1 and E2 proteins are required for replication of bovine pa pillomavirus type 1 DNA. Both proteins bind as a complex to the replic ation origin, which consists of an El binding site flanked on either s ide by E2 binding sites. The E1 protein has properties common to repli cation initiator proteins such as sequence-specific origin binding and DNA helicase activities. The E2 protein is a transcriptional transact ivator that forms a complex with the E1 protein and enhances binding o f E1 to the replication origin. We have mapped the regions of the E1 p rotein required for sequence-specific DNA binding, for cooperative bin ding with the E2 protein to the origin region, and for interaction wit h the E2 protein. These studies demonstrate that a region between amin o acids 162 and 378 of the E1 protein is important for origin-specific DNA binding. The C-terminal half of the E1 protein is required in add ition to the DNA binding domain (residues 162 to 605) for cooperative binding to the origin with the E2 protein. Binding studies confirmed t hat this region is also required for efficient complex formation with the E2 protein. (C) 1995 Academic Press, Inc.