The middle subunit of replication protein A contacts growing RNA-DNA primers in replicating simian virus 40 chromosomes.
The eukaryotic single-stranded DNA binding protein replication protein A (RPA) participates in major DNA transactions. RPA also interacts through its middle subunit (Rpa2) with regulators of the cell division cycle and of the response to DNA damage. A specific contact between Rpa2 and nascent simian virus 40 DNA was revealed by in situ UV cross-linking. The dynamic attributes of the cross-linked DNA, its size distribution, its RNA primer content, and its  replication fork polarity were determined [corrected]. These data suggest that Rpa2 contacts the early DNA chain intermediates synthesized by DNA polymerase alpha-primase (RNA-DNA primers) but not more advanced products. Possible signaling functions of Rpa2 are discussed, and current models of eukaryotic lagging-strand DNA synthesis are evaluated in view of our results.
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Department of Biochemistry, Tel Aviv University, Ramat Aviv 69978, Israel.
Nethanel
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Kaufmann
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D003432:Cross-Linking Reagents / Q000378:metabolism; D019915:DNA Primase / Q000235:genetics; D004261:DNA Replication / Q000235:genetics*; D004279:DNA, Viral / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D019920:Photoaffinity Labels / Q000378:metabolism; D012313:RNA / Q000235:genetics; D051716:Replication Protein A; D013539:Simian virus 40 / Q000235:genetics*; D014466:Ultraviolet Rays
D003432:Cross-Linking Reagents; D004279:DNA, Viral; D004268:DNA-Binding Proteins; D019920:Photoaffinity Labels; C034477:RNA primers; D051716:Replication Protein A; D012313:RNA; D019915:DNA Primase