Abstract: |
DNA polymerase δ requires proliferating cell nuclear antigen and replication factor C to form a holoenzyme efficient in DNA synthesis. We have analyzed three different aspects of calf thymus DNA polymerase δ holoenzyme: (i) analysis of pausing during DNA synthesis, (ii) replication of double-stranded DNA in the absence of additional factors, and (iii) replication of double-stranded DNA in the presence of the two known replicative DNA helicases from simian virus 40 and bovine papilloma virus. DNA polymerase δ holoenzyme replicated primed single-stranded DNA at a rate of 100-300 nucleotides/min, partially overcoming multiple pause sites on DNA. While Escherichia coli single-strand DNA binding protein helped DNA polymerase δ pass through pause sites, the DNA polymerase δ itself appeared to dissociate from the template in the absence of synthesis or when encountering pause sites. Proliferating cell nuclear antigen likely remained on the template. DNA polymerase δ holoenzyme could perform limited strand displacement synthesis on double-stranded gapped circular DNA, and this reaction was not stimulated either by replication protein A or by E. coli single-strand DNA binding protein. DNA polymerase δ holoenzyme could efficiently cooperate with replicative DNA helicases from simian virus 40 (large T antigen) and bovine papilloma virus 1 (protein El) in replication through double-stranded DNA in a reaction that required replication protein A or E. coli single-strand DNA binding protein. Our data are consistent with the role of DNA polymerase δ as the leading strand replicase but also suggest that additional factors [e.g., proteins to pass pause sites and cellular DNA helicase(s)] might be required to achieve replication at a physiological speed. © 1995, American Chemical Society. All rights reserved. |
Keywords: |
dna binding protein; dna-binding proteins; nonhuman; dna polymerase; dna replication; dna synthesis; enzyme activity; dna; double stranded dna; escherichia coli; virus large t antigen; simian virus 40; helicase; cycline; single stranded dna; dna, single-stranded; dna helicases; proliferating cell nuclear antigen; papilloma virus; dna-directed dna polymerase; templates, genetic; bacteriophage t4; dna polymerase iii; dna, circular; priority journal; article; support, non-u.s. gov't; support, u.s. gov't, p.h.s.; papillomavirus, bovine
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