DNA polymerase has entry site available PPP.OH 13.4 DNA polymerases 5'.P PP PP OH3' control the fidelity of 235 replication Nucleotide enters and forms bond 5}m.BP巳PPP-3OH 3D233P5 igure 13.6 Bacterial DNA Enzyme advances 1 nucleotide polymerases scrutinize the "3'oH base pair at the end of the 88g Pb229 5 growing chain and excise the nucleotide added in the case Mismatch causes removal of nucleotide; enzyme retreats 1 bp OH 5!.PPPPP OH3' 清菜大当 33是5
Figure 13.6 Bacterial DNA polymerases scrutinize the base pair at the end of the growing chain and excise the nucleotide added in the case of a misfit. 13.4 DNA polymerases control the fidelity of replication
13.3 DNA polymerases have various nuclease activities 3 HHHHHHHHHHHHHHHH Nick generates 3-OH,5'P groups OHP 3HHHH田HHHHHHHHHHH田 6 DNA synthesis extends 3'end; old strand is degraded 3 HHHHHHHHHH✉HH田 L S Figure 13.5 Nick translation replaces part of a pre-existing strand of duplex DNA with newly synthesized material 情菜大当
Figure 13.5 Nick translation replaces part of a pre-existing strand of duplex DNA with newly synthesized material. 13.3 DNA polymerases have various nuclease activities
13.3 DNA polymerases have various nuclease activities Table 15.1 Proofreading reduces the errors made by DNA polymerases. Enzyme Locations of synthetic Error rate proofreading domains proofreading proofreading E.coli DNA polymerase I single subunit 105 5×107 E.coli DNA polymerase Ill separate subunits 7x106 5×109 T4 DNA polymerase single subunit 5x105 10-7 T7 DNA polymerase unknown 105 10-6 Reverse transcriptase none 10-5 清菜大兰
13.3 DNA polymerases have various nuclease activities
13.3 DNA polymerases have various nuclease activities Table 15.2 There are 5 mammalian DNA polymerases(identified by Greek letters;yeast equivalents are given Roman numerals). DNA Polymerase a δ(I) e() B Location Nuclear Nuclear Nuclear Nuclear Mitochondrial Synthetic function Priming DNA synthesis Repair Repair Replication Other functions 3'-5'exonuclease 3'-5'exonuclease 3'-5'exonuclease Inhibitors aphidicolin aphidicolin aphidicolin dideoxy-TTP dideoxy-TTP 清菜大当
13.3 DNA polymerases have various nuclease activities
13.8 Priming is required to start 3 HHHHHHHHHHH1I号 DNA synthesis 5 LLLLLL115 RNA DNA HHHHHHHHHHEBnnno Figure 13.12 There are P6A形品智Yi中 several methods for Nick providing the free 3 OH end that DNA AHHH旺g polymerases require to 5' 清菜大当
Figure 13.12 There are several methods for providing the free 3 - OH end that DNA polymerases require to initiate DNA synthesis. 13.8 Priming is required to start DNA synthesis