DNA Replication and Synthesis

•Complementarity

•”It has not escaped our notice that the specific pairing we have postulated immediately suggests a possible copying mechanism … “

•Mode of DNA Replication

•Conservative

•Semiconservative

•Dispersive

*Overview: DNA replication

*Overview: DNA replication

Origin and DirectionReplication fork

Replicon

DNA Polymerases

•chain elongation in a 5’-to-3’ direction•biological activity?

DNA Polymerase

Exonuclease Activities of

DNA Polymerases

Initiation

*Strands must separate•DnaA•Helicases (DnaB and DnaC)•SSBPs (DnaA)•Topoisomerase (DNA gyrase)

*Primase

*Two strands of a double helix are antiparallel

•Continuous DNA synthesis = leading•Discontinuous DNA synthesis = lagging

Initiation