分子学（渥太华大学）L4-DNA replication.pdf

文档介绍：Lecture IV:
DNA
Replication
Contact information:
Dr. Josée Coutu
Gendron Hall, room 170A
josee.******@
The Meselson and Stahl Experiment
DNA replication is
semi-conservative
Coutu – DNA Replication 1
DNA templating
Coutu – DNA Replication 2
DNA synthesis - Overview
Why does DNA synthesis only proceed in the 5’ to 3’ direction?
Coutu – DNA Replication 3
Directional Synthesis
Coutu – DNA Replication 4
The replication fork
Replication is bidirectional
Coutu – DNA Replication 5
The replication fork
Both strands cannot be replicated in a continuous fashion!
Coutu – DNA Replication 6
Semidiscontinuous replication
Okazaki fragments
- 1000 to 2000 nts (prokaryotes) and 100 to 200 nts (eukaryotes)
Coutu – DNA Replication 7
Discontinuous Replication
PRIMASE = synthesis of primers
Coutu – DNA Replication 8
Prokaryotic Replication: DNA Polymerase
The structure of DNA polymerase, as
determined by X-ray crystallography. It
resembles a right hand in which the palm,
fingers, and thumb grasp DNA (= a fist).
Coutu – DNA Replication 9