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Article
RNA Primer Handoff in Bacteriophage T4 DNA Replication
Journal of Biological Chemistry (2008)
  • Scott W. Nelson, Pennsylvania State University - Main Campus
  • Ravindra Kumar, Pennsylvania State University - Main Campus
  • Stephen J. Benkovic, Pennsylvania State University - Main Campus
Abstract
In T4 phage, coordinated leading and lagging strand DNA synthesis is carried out by an eight-protein complex termed the replisome. The control of lagging strand DNA synthesis depends on a highly dynamic replisome with several proteins entering and leaving during DNA replication. Here we examine the role of single-stranded binding protein (gp32) in the repetitive cycles of lagging strand synthesis. Removal of the proteininteracting domain of gp32 results in a reduction in the number of primers synthesized and in the efficiency of primer transfer to the polymerase. We find that the primase protein is moderately processive, and this processivity depends on the presence of fulllength gp32 at the replication fork. Surprisingly, we find that an increase in the efficiency of primer transfer to the clamp protein correlates with a decrease in the dissociation rate of the primase from the replisome. These findings result in a revised model of lagging strand DNA synthesis where the primase remains as part of the replisome after each successful cycle of Okazaki fragment synthesis. A delay in primer transfer results in an increased probability of the primase dissociating from the replication fork. The interplay between gp32, primase, clamp, and clamp loader dictates the rate and efficiency of primer synthesis, polymerase recycling, and primer transfer to the polymerase.
Keywords
  • Bacteriophages,
  • DNA,
  • Genes,
  • Nucleic acids,
  • Polymers,
  • DNA replications,
  • Lagging strands,
  • Okazaki fragments,
  • bacteriophage T4,
  • DNA replication
Publication Date
May, 2008
DOI
10.1074/jbc.M802762200
Publisher Statement
This article is from Journal of Biological Chemistry 283 (2008): 22838, doi:10.1074/jbc.M802762200. Posted with permission.
Citation Information
Scott W. Nelson, Ravindra Kumar and Stephen J. Benkovic. "RNA Primer Handoff in Bacteriophage T4 DNA Replication" Journal of Biological Chemistry Vol. 283 Iss. 33 (2008) p. 22838 - 22846
Available at: http://works.bepress.com/scott-nelson/3/