DNA Replication Repair Recombination Dr Kevin Ahern Structure

DNA Replication, Repair & Recombination Dr. Kevin Ahern

Structure

Structure

Structure One Strand of DNA

Structure • Introduction

Structure • Introduction

DNA Structure

DNA Forms

Semi-Conservative Replication Discontinuous Replication on Lagging Strand (Okazaki Fragments) Continuous Replication on Leading Strand

Leading and Lagging Strand DNA Replication Leading Strand Lagging Strand

DNA Replication

DNA Replication

DNA Replication

DNA Polymerase I

DNA Polymerase I Structure

DNA Replication Proteins

Replication Fork

Beta Clamp Top View DNA Side View

Chemical Mechanism of Chain Elongation

Leading / Lagging Strand Replication

DNA Topoisomers

Topoisomerase Action

Topoisomers/Topoisomerases L = T+W L = Linking Number T = Twists W = Writhes

Polymerase Chain Reaction

Polymerase Chain Reaction

Polymerase Chain Reaction

Polymerase Chain Reaction

Polymerase Chain Reaction

DNA Proof-reading

Prokaryotic vs Eukaryotic DNA Replication • Introduction

Chromosomes With Telomeres

Linear DNA Replication

Telomerase Action

Telomerase Action

Nucleotide Excision Repair Bulky DNA Adduct

Nucleotide Excision Repair

Nucleotide Excision Repair

Nucleotide Excision Repair • Thymine Dimers

Nucleotide Excision Repair Thymine Dimer Repair Partial Strand Removal

Base Excision Repair Cytosine Deamination Cytosine Uracil

Flipping out of base from helix Base Excision Repair

Excision of Base Excision Repair Uracil-N-Glycosylase Catalysis

DNA Mismatch Repair Mismatch

DNA Mismatch Repair Unmethylated, recognizable Methylated, unrecognizable

Measuring Mutation Ames Test

DNA Recombination

DNA Recombination • Strand Invasion

Structure • Introduction

DNA Recombination • Holliday Junction

Recombination/Repair

Rec. A Recombination Repair in E. coli