2.1 Enzymology of DNA Replication Enzyme Helicase Topoisomerase SSB Primase DNA-dependent DNA polymerase (DDDP) Ligase protein factor
§2.1 Enzymology of DNA Replication Enzyme : Helicase Topoisomerase SSB Primase DNA-dependent DNA polymerase (DDDP) Ligase protein factor
2.1.1 Helicase It is with ATPase activity DnaB is main enzyme in E.coli DNA replication. It unwinds the double strand DNA and help primase to get access to DNA template. The opening process with the assistance of DnaA and DnaC In eukaryote:MCM helicase
2.1.1 Helicase It is with ATPase activity DnaB is main enzyme in E.coli DNA replication. It unwinds the double strand DNA and help primase to get access to DNA template. The opening process with the assistance of DnaA and DnaC In eukaryote: MCM helicase
2.1.2 Topoisomerase Topoisomerase:Topo,cleave and reseal DNA strands Release the supercoil constraint ahead of replication forks
2.1.2 Topoisomerase Topoisomerase: Topo，cleave and reseal DNA strands . Release the supercoil constraint ahead of replication forks
Topoisomerase functions in a three-step process: 1.Cleavage of one or both strands of DNA 2.Passage of a segment of DNA 3.Resealing of the DNA break
Topoisomerase functions in a three-step process: 1.Cleavage of one or both strands of DNA 2. Passage of a segment of DNA 3. Resealing of the DNA break
Classification:Topo I and TopoI Topo I:Also called @-proteinin prokaryotes. It cuts one DNA strand,allows the broken DNA strand to rotate around the other strand to relax the constraint,and then reseals the cut. Without consuming ATP. Topoisomerase (type l) Anticancer drug: Camptothecin: Binding and OH Rotation of igation an topotecan nicking free 3'end Irinotecan
Classification: Topo I and TopoⅡ Topo I: Also called -proteinin prokaryotes. It cuts one DNA strand, allows the broken DNA strand to rotate around the other strand to relax the constraint, and then reseals the cut. Without consuming ATP. Anticancer drug: Camptothecin： topotecan Irinotecan