The Replication System of Bacteriophage T7.

ABSTRACT

The replication system of bacteriophage T7 is remarkable in that the 40,000 nucleotide genome is replicated over 100-fold in a matter of minutes. In order to accomplish this feat T7 has evolved an efficient and economical process for the replication of its DNA. The T7 replisome provides a model system to study DNA replication. Four proteins are sufficient for reconstitution of the functional replication complex, yet the assembled replisome recapitulates all the key features of more complex prokaryotic and eukaryotic systems. In this review, we describe chemical mechanisms employed by individual proteins at the replication fork. Integration of structural, biochemical, and single-molecule data reveals a compelling view on how a nearly 1-MDa molecular machine acts as a unit to synthetize the two antiparallel DNA strands in a coordinated fashion.