E. coli primase and DNA polymerase III holoenzyme are able to bind concurrently to a primed template during DNA replication

Scientific Reports. 2019;9(1):1-12 DOI 10.1038/s41598-019-51031-0

 

Journal Homepage

Journal Title: Scientific Reports

ISSN: 2045-2322 (Online)

Publisher: Nature Publishing Group

LCC Subject Category: Medicine | Science

Country of publisher: United Kingdom

Language of fulltext: English

Full-text formats available: PDF, HTML

 

AUTHORS


Andrea Bogutzki (Institute for Biophysical Chemistry, Hannover Medical School)

Natalie Naue (Institute for Biophysical Chemistry, Hannover Medical School)

Lidia Litz (Institute for Biophysical Chemistry, Hannover Medical School)

Andreas Pich (Institute for Toxicology, Hannover Medical School)

Ute Curth (Institute for Biophysical Chemistry, Hannover Medical School)

EDITORIAL INFORMATION

Blind peer review

Editorial Board

Instructions for authors

Time From Submission to Publication: 20 weeks

 

Abstract | Full Text

Abstract During DNA replication in E. coli, a switch between DnaG primase and DNA polymerase III holoenzyme (pol III) activities has to occur every time when the synthesis of a new Okazaki fragment starts. As both primase and the χ subunit of pol III interact with the highly conserved C-terminus of single-stranded DNA-binding protein (SSB), it had been proposed that the binding of both proteins to SSB is mutually exclusive. Using a replication system containing the origin of replication of the single-stranded DNA phage G4 (G4ori) saturated with SSB, we tested whether DnaG and pol III can bind concurrently to the primed template. We found that the addition of pol III does not lead to a displacement of primase, but to the formation of higher complexes. Even pol III-mediated primer elongation by one or several DNA nucleotides does not result in the dissociation of DnaG. About 10 nucleotides have to be added in order to displace one of the two primase molecules bound to SSB-saturated G4ori. The concurrent binding of primase and pol III is highly plausible, since even the SSB tetramer situated directly next to the 3′-terminus of the primer provides four C-termini for protein-protein interactions.