| Abstract: |
Replication of bovine papilloma virus (BPV) DNA requires two virus-encoded proteins, E1 and E2, while all other proteins are supplied by the host cell. Here, we describe the isolation of the E1 protein and show that it is a multifunctional protein. Purified E1 protein was required for the in vitro replication of BPV origin-containing DNA by extracts of mouse cells, as reported [Yang, L., Li, R., Mohr, I. J., Clark, R. & Botchan, M. R. (1991) Nature (London) 353, 628-632]. In addition, the E1 protein cosedimented with a number of other activities including (i) DNA helicase activity, (ii) BPV origincontaining DNA-specific binding activity, (iii) DNA-dependent ATPase activity, and (iv) BPV origin-specific unwinding of superhelical DNA. The E1 protein, acting as a helicase, moved in the 3′ → 5′ direction, like simian virus 40 (SV40) large tumor antigen, which plays a pivotal role in SV40 DNA replication. However, unlike the SV40 large tumor antigen, the helicase activity of E1 was stimulated 5-fold by the presence of a fork structure at the junction between single-stranded and double-stranded DNA and was supported efficiently by all eight nucleoside triphosphates. The E1-catalyzed ATPase activity required the presence of single-stranded or double-stranded DNAs. |
| Keywords: |
dna-binding proteins; nonhuman; dna replication; animal cell; mouse; animal; mice; cell line; double stranded dna; amino acid sequence; molecular sequence data; protein purification; virus large t antigen; simian virus 40; base sequence; dna, viral; virus replication; helicase; single stranded dna; nucleic acid conformation; adenosine triphosphatase; dna helicases; dna helicase; protein isolation; virus protein; viral proteins; dna denaturation; virus dna; papilloma virus; bovinae; cell-free system; papillomavirus; simiae; simian virus; priority journal; article; support, non-u.s. gov't; support, u.s. gov't, p.h.s.; adenosinetriphosphatase; papillomavirus, bovine; origin binding; bovine parvovirus; highly unwound superhelical dna; bovine papilloma virus; polarity of translation
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