Sunday, March 24, 2013

DNA Replication-- Summary

The following are the summary of what happens during DNA replication:

  1. Starting from the origin of replication (ori), helicase unwinds the the double helix. Single-stranded bonding proteins (SSBPs) bind to the single stranded DNA to keep them apart.
  2. RNA polymerase constructs RNA primers on both leading and lagging strands
    • The leading strand is continuously elongated by DNAP III.
    • The lagging strand is elongated discontinuously. Each okazaki segment is primed with RNAP, and then elongated by by DNAP III. DNAP I replaces the RNA primer with DNA, and DNA ligase joins the fragments together by catalyzing the formation of phosphodiester bonds.
  3. This process continues until the replication fork meets the replication fork of another replication bubble, or when the end of the DNA strand is reached.