Enzymatic Recognition of DNA Replication Origins
This extract was created in the absence of an abstract.
Excerpt
We have studied the initiation of DNA synthesis in two systems: (1) conversion of the single-stranded (SS) DNA coliphage chromosomes to their duplex replicative forms (RFI) and (2) replication of plasmids containing the Escherichia coli chromosomal origin.
The in vitro SS to RF conversions of phages M13, G4, and ϕX174 provide attractive models for discontinuous DNA replication in E. coli. In each instance, the DNA must first be covered with single-stranded DNA-binding protein (SSB). SSB-coated, M13 SS DNA is transcribed by RNA polymerase to yield a short, unique RNA primer at the complementary-strand origin (Geider and Kornberg 1974). SSB-coated G4 SS DNA is recognized and primed by primase, the product of the E. coli dnaG gene (Zechel et al. 1975). Primase, in conjunction with six prepriming proteins, also primes SSB-coated ϕX viral DNA (Meyer et al. 1979). In each of these systems, the RNA primer is elongated by DNA polymerase...
