SEQUENTIAL INITIATION OF LAGGING AND LEADING STRAND SYNTHESIS BY 2 DIFFERENT POLYMERASE COMPLEXES AT THE SV40 DNA-REPLICATION ORIGIN

Enzymatic synthesis of DNA from the simian virus 40 origin of DNA replication has been reconstituted in vitro with eight purified components. DNA polymerase α-primase complex first initiates DNA synthesis at the replication origin and continues as the lagging strand polymerase. Subsequently, the DNA polymerase δ complex initiates replication on the leading strand template. Some prokaryotic DNA polymerase complexes can replace the eukaryotic polymerase δ complex. A model for polymerase switching during initiation of DNA replication is presented. © 1990 Nature Publishing Group.