1. 18 and 20 September, 2006 Chapter 8 DNA Replication

2. Overview DNA synthesis requires, primer, template, and dNTPs, and proceeds in the 5’ to 3’ direction on the new strand. The DNA polymerase active site is specific for correctly paired, deoxy nucleotides. DNA polymerase catalysis involves base pairing, and stabilization of the transition state by divalent cations. DNA polymerase is processive, and has a 3’ exonuclease proofreading activity. Synthesis proceeds simultaneously on the leading and lagging strands. DNA synthesis requires Helicase, Primase, SSB, and Topoisomerase. Specialized DNA polymerases have specialized roles in the cell. Sliding clamps increase processivity. Pol III holoenzyme is composed of two pol III cores, a clamp and a clamp loader. The replisome is a complex group of protein activities. DNA replication initiates at origin of replication sequences. DNA replication is highly regulated. Replication of the ends of linear DNA molecules requires special solutions.

3. DNA Polymerase Substrates

4. DNA Polymerase Reaction

5. Base pairing in the DNA Polymerase Active Site

6. Selection of DNA Monomers

7. DNA Polymerase Structure Includes two Divalent Cation Cofactors.

8. Stabilizing the Transition State

9. Processive Polymerase and Exonuclease Activity

10. Discontinuous Replication

11. Primer Replacement

12. Helicase

13. SSB

14. Topoisomerase

15. Primer Synthesis and Polymerase Exchange

16. Sliding Clamp

17. DNA polymerases

18. The sliding clamp promotes processivity.

20. Core and Clamp Loading Subunits

21. Coordination of Leading and Lagging Strand Synthesis

28. The animation really is worth more that one thousand words.

29. Origin of Replication

32. Assembly of replication complexes

33. DNA must be replicated before anaphase..

35. Regulation of replication.

36. Replicating the Ends of Linear DNA

37. Assay for helicase activity and polarity

39. ATP control of the clamp loader

40. Cloning a Replication Origin

41. Electrophoretic Analysis of Replication.

42. Methylation

43. Multiple Rounds of Replication