ORIGIN AND INCEPTOR OF DNA REPLICATION IN BACTERIOPHAGE LAMBDA

Hybrid plasmid dissection and reconstruction pro-cedures have shown that two different signal structures for initiation of DNA replication can be separated within the replicator region of various lambdoid phages. From our hybrid plasmid experiments we conclude that the origin of replication (ori) serves as the initiation site for leftward primer RNA synthesis while the replicational inceptor (iae) signal controls termination of that primer RNA and inception of daughter strand DNA synthesis. Hybrid plasmids containing only ori are unable to initiate lambdoid replication, whereas plasmids containing iae in connection with a leftward promoter do show replicational activity (minimal replication system).