Discrete interactions between bacteriophage T7 primase-helicase and DNA polymerase drive the formation of a priming complex containing two copies of DNA polymerase.

ABSTRACT: Replisomes are multiprotein complexes that coordinate the synthesis of leading and lagging DNA strands to increase the replication efficiency and reduce DNA strand breaks caused by stalling of replication forks. The bacteriophage T7 replisome is an economical machine that requires only four proteins for processive, coupled synthesis of two DNA strands. Here we characterize a complex between T7 primase-helicase and DNA polymerase on DNA that was trapped during the initiation of Okazaki fragment synthesis from an RNA primer. This priming complex consists of two DNA polymerases and a primase-helicase hexamer that assemble on the DNA template in an RNA-dependent manner. The zinc binding domain of the primase-helicase is essential for trapping the RNA primer in complex with the polymerase, and

SUBMITTER: Wallen JR 

PROVIDER: S-EPMC3750080 | biostudies-literature | 2013 Jun

REPOSITORIES: biostudies-literature