ANATOMY OF A DNA-REPLICATION FORK REVEALED BY RECONSTITUTION OF SV40 DNA-REPLICATION IN-VITRO

Complete enzymatic replication of DNA from the simian virus 40 origin has been reconstituted with T antigen and highly purified cellular pro teins. DNA polymerase-alpha/primase functions primarily to synthesize RNA-DNA primers for initiation of DNA replication at the origin and fo r priming each Okazaki fragment. A polymerase switching mechanism requ iring replication factor C and the proliferating cell nuclear antigen allows two molecules of DNA polymerase-delta to replicate both strands of the double helix conjointly.