Summary of DNA synthesis in bacteria.
- At the advancing fork, helicase proteins unwind the double helix.
- Primase lays down a short RNA primer.
- Each core enzyme of the DNA polymerase III dimer is bound to a template strand by a beta-subunit
- Synthesis is continuous on the leading strand, but occurs in
Okazaki fragments on the lagging strand.
- The lagging strand loops around to allow concurrent synthesis on both strands.
- DNA polymerase I replaces the RNA primer (synthesized by primase) with DNA.
- DNA ligase joins the Okazaki fragments.