Chapter 5 Macromolecules and Molecular Genetics DNA Replication Complementary base pairing Semiconservative Template and primer From 5-phosphate to the 3 -hydroxyl end dNa polymerase and ligase A short stretch of rna serves as a primer Primase: a specific RNA-polymerizing enzyme
Chapter 5 Macromolecules and Molecular Genetics DNA Replication Complementary base pairing Semiconservative Template and primer From 5’-phosphate to the 3’-hydroxyl end DNA polymerase and ligase A short stretch of RNA serves as a primer Primase: a specific RNA-polymerizing enzyme
Initiation of DNA synthesis 1. Origin of replication 300 bases with specific 2. DNA double helix opens up at the origin of replication Primase 3. Replication fork (left) 4. Bidirectional replication Single-stranded binding prot 5. Theta structure in DNA polymerase circular dna 6. Single eukaryotic 3 chromosome has many origins 7. Replication is carefully regulated 3
Initiation of DNA synthesis 1. Origin of replication: 300 bases with specific sequence; 2. DNA double helix opens up at the origin of replication 3. Replication fork (left) 4. Bidirectional replication 5.Theta structure in circular DNA 6. Single eukaryotic chromosome has many origins 7. Replication is carefully regulated
Ongin of DNA replication process 1. Leading strands: 5'-P3-OH 2. Lagging strands: 5-PRNA 3-OH Newly syn 3. DNA polymerase I,Il,III orks Ongin eac Leading Lagging Direchon Replication Replication fork
DNA replication process 1. Leading strands: 5’-P 3’-OH 2. Lagging strands: 5’-P RNA 3’-OH 3. DNA polymerase I, II, III
Leading and Lagging Strands Leading strand: DNa synthesis occurs continuously from the 5 -phosphate to the 3-hydroxyl Lagging strand: DNA synthesis occurs discontinuously Enzymes in lagging strand synthesis DNA primase, DNA polymerase III and I, DNA ligase
Leading and Lagging Strands Leading strand: DNA synthesis occurs continuously from the 5’-phosphate to the 3’-hydroxyl; Lagging strand: DNA synthesis occurs discontinuously. Enzymes in lagging strand synthesis: DNA primase, DNA polymerase III and I, DNA ligase
DNA polymerase Ill RNA pn 3-0H 5-P Kazak F raguel Single-stranded binding prote DNA polymerase I Heics DNA polymerase Free 3-OH Enzymes in lagging strand synthesis DNA primase 13 DNA polymerase III and I DNA ligase
Okazaki Fragment Enzymes in lagging strand synthesis: DNA primase, DNA polymerase III and I, DNA ligase