Mitochondrial DNA replication starts at a D-loop Completion of new L strand releases daughter genomes RNA primer initiates RNA synthesis initiated replication at origin on H strap Completion Released genofne is RNA cleaved L strand((H strand generates partially replicat duplex circl Completi generates DNA is synthesized duplex circle Synthesis of new L strand Gaps in new strands are sealed creates D loop by displacing parental strand swirtualtexwww.ergitocom D loop expands Figure 13.11 The d loop maintains an opening in mammalian mitochondrial DNA, which has separate origins for the replication of each strand Download L strand origin When displaced strand its name as the passes origin on L strand, synthesis of displacement or D new H strand starts loop
◼ its name as the displacement or D loop
5解决线性DNA的起始复制问题) Replication of a 5 end is a problem 8800880008 End of linear DNA How does a new strand 5 initiate at the end Run off 5 New strand synthesized 5-3 5 Cvirtuahextwww.ergitooom PPPP早P Figure 13.12 Replication could run off the 3 end of a newly synthesized linear strand, but could it initiate at a 5' end? Download
5 解决线性DNA的起始复制问题）
Priming(引导) is required to start DNA synthesis RNA引导:前导链及所有的后随链片段的DNA合成都由短的 RNA片段引导起始,然后沿DNA模板延伸。引物在连接前被 去掉并填补上DNA。这种机制有助于保持高度的复制保真 性 All dNa polymerases require a 3-OH priming end to initiate DNA synthesis The priming end can be provided by an rna primer, a nick in DNA or a priming protein For dna replication, a special rna polymerase called a primase synthesizes an rna chain that provides the priming end
◼ RNA引导：前导链及所有的后随链片段的DNA合成都由短的 RNA片段引导起始，然后沿DNA模板延伸。引物在连接前被 去掉并填补上DNA。这种机制有助于保持高度的复制保真 性。 ◼ All DNA polymerases require a 3 –OH priming end to initiate DNA synthesis. ◼ The priming end can be provided by an RNA primer, a nick in DNA, or a priming protein. ◼ For DNA replication, a special RNA polymerase called a primase synthesizes an RNA chain that provides the priming end. Priming（引导） is required to start DNA synthesis