Termination complex in Escherichia coli inhibits SV40 DNA replication in vitro by impeding the action of T antigen helicase.
DNA replication terminus (ter)-binding protein (TBP) in Escherichia coli binds specifically to the terminus (ter) site, and the resulting complex severely blocks DNA replication in an unique orientation by inhibiting the action of helicases. To generalize the intrinsic nature of the orientated ter-TBP complex against various helicases, we tested the potential of the complex to inhibit the action of three helicases, DNA helicase I, simian virus 40 (SV40) large tumor (T) antigen, and helicase B, derived from F plasmid, SV40, and mouse FM3A cell, respectively. The complex impeded the unwinding activities of all tested helicases in a specific orientation, with the same polarity observed in case of blockage of a replication fork, and, as a result, there was a block of SV40 DNA replication in both crude and purified enzyme systems in vitro. As the specificity in polarity of inhibition extends to heterologous systems, there may be common structure/mechanism features in helicases.
Hidaka
M
M
Laboratory of Gene Expression and Regulation, National Institute for Basic Biology, Okazaki, Japan.
Kobayashi
T
T
Ishimi
Y
Y
Seki
M
M
Enomoto
T
T
Abdel-Monem
M
M
Horiuchi
T
T
D000952:Antigens, Polyomavirus Transforming / Q000378:metabolism*; D001483:Base Sequence; D001665:Binding Sites; D004265:DNA Helicases / Q000378:metabolism*; D004261:DNA Replication; D004279:DNA, Viral / Q000235:genetics; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins; D007700:Kinetics; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D010957:Plasmids; D013539:Simian virus 40 / Q000235:genetics*; D013379:Substrate Specificity; D013728:Terminator Regions, Genetic
D000952:Antigens, Polyomavirus Transforming; C062011:DNA replication terminus site-binding protein, E coli; D004279:DNA, Viral; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D009838:Oligodeoxyribonucleotides; D004265:DNA Helicases