Outline

Introduction

Information Metabolism: The Major Processes (Figure 4.23)

An Overview of DNA Replication (Figure 24.1, Figure 4.12, Figure 4.13, Figure 4.14, Figure 24.2, Figure 24.3, Figure 24.4, Figure 24.5, Figure 24.6)

A Review of Genetic Terminology (Figure 24.7, Figure 24.8)

Early Insights into DNA Replication

> Semiconservative Nature of DNA Replication

> Sequential Nature of Replication (Figure 24.9)

> Origin and Direction of Replication

> Units of Replication: The Replicon (Figure 24.13, Table 24.1)

DNA Polymerases: Enzymes Catalyzing Polynucleotide Chain Elongation

> Discovery of DNA Polymerase

> Structure and Activities of DNA Polymerase I

> > DNA Substrates for the Polymerase Reaction (Figure 24.15)

> > Multiple Activities in a Single Polypeptide Chain

> > Structure of DNA Polymerase I

> DNA Polymerases II and III (Table 24.2)

> Structure and Mechanism of DNA Polymerases

> The DNA Polymerase III Holoenzyme

> Eukaryotic DNA Polymerases (Table 24.3)

Replication Proteins Other than DNA Polymerases (Figure 24.23, Figure 22.23)

> DNA Ligase: Discontinuous Replication of DNA (Figure 24.3, Figure 24.24)

> Primase: Synthesis of RNA Leader Sequences (Figure 24.25, Figure 24.5)

> Clamps and Clamp Loaders: Processivity

> Single-Strand DNA-Binding Proteins: Maintaining Optimal Template Conformation (Figure 24.26)

> Helicases: Unwinding DNA Ahead of the Fork (Figure 24.27, Figure 24.28)

> Topoisomerases: Relieving Torsional Stress

> > Actions of Type I and Type II Topoisomerases (Figure 24.30, Figure 24.31)

> > The Four Topoisomerases of E. coli (Figure 24.33, Figure 24.34)

> Uracil-DNA N-Glycosylase: Removal of Incorporated Uracil (Figure 24.35)

Reconstruction of Replication Machines (Figure 24.6, Figure 24.36)

Initiation of DNA Replication

> Requirements for Initiation of Replication

> Initiation of E. coli DNA Replication at oric (Figure 24.37)

> Plasmid DNA Replication: Control of Initiation by RNA (Figure 24.38)

> Mitochondrial DNA: Two Unidirectional Replication Forks (Figure 24.39)

Replication of Linear Genomes (Figure 24.40, Figure 24.41ab, Figure 24.41c, Figure 24.42)

Fidelity of DNA Replication (Figure 24.44)

RNA Viruses: The Replication of RNA Genomes

> RNA-Dependent RNA Replicases

> Replication of Retroviral Genomes (Figure 24.45)