1 / 14

Homologous Recombination

Homologous Recombination. MCB 7200 Group 1 Ashley Patton Yanyang Cuo Samantha Shaw. Homologous Recombination. Biological Relevance Repairs double-stranded breaks Chromosome segregation during meiosis I Genetic diversity in gametes Mediated by two important enzymes Rad51 and Dmc1

evangeline-pugh
Download Presentation

Homologous Recombination

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. HomologousRecombination MCB 7200 Group 1 Ashley Patton Yanyang Cuo Samantha Shaw

  2. Homologous Recombination • Biological Relevance • Repairs double-stranded breaks • Chromosome segregation during meiosis I • Genetic diversity in gametes • Mediated by two important enzymes • Rad51 and Dmc1 • Occurs during late-S phase, G2, M Filippo et al. 2008. Mechanism of Eukaryotic Homologous Recombination

  3. Construction of P. falciparum expression vectors

  4. Homologous Recombination • Double Strand Break Repair • Synthesis-dependent strand annealing • Migrating D loop • No Holiday Junction formation • Mitosis/Meiosis • Single strand annealing • Repair of double strand break by deletion of repeated DNA sequences • No Holiday Junction formation • Break-induced repair • Telomeres • Replication forks

  5. Homologous Recombination Mechanism Filippo et al. 2008. Mechanism of Eukaryotic Homologous Recombination

  6. Prokaryotic Recombination • RecBCD • Helicase activity unwinds DNA • Exonuclease activity degrades both single strands • At CHI site • 3′ - 5′ Exonuclease activity is inhibited • 5′ -3′ activity enhanced yielding a single-stranded 3′ end. • This end becomes coated with multiple RecA proteins, which catalyze strand invasion and formation of a Holliday structure Lodish et al., Molecular Cell Biology, 4th Fig 12-32

  7. Prokaryotic Recombination • RecA • RecA binds ssDNA in the presence of ATP • RecA aligns the ssDNA with its homologous dsDNA region • RecA inserts the ssDNA into target DNA sequence forming a heteroduplex Holiday-type structure • Branch Migration and Resolution by RuvA,B,C Lodish et al., Molecular Cell Biology, 4th Fig 12-35

  8. http://www.qiagen.com/products/genes%20and%20pathways/pathway%20details.aspx?pwid=143http://www.qiagen.com/products/genes%20and%20pathways/pathway%20details.aspx?pwid=143

  9. http://www.qiagen.com/products/genes%20and%20pathways/pathway%20details.aspx?pwid=143http://www.qiagen.com/products/genes%20and%20pathways/pathway%20details.aspx?pwid=143

  10. Filippo et al. 2008. Mechanism of Eukaryotic Homologous Recombination

  11. Summary • Used for double strand break repair and genetic diversity in meiosis. • Different mechanisms within the Eukaryotic and Prokaryotic cells. • Proteins are different with each system by have similar functions.

  12. Summary: Prokaryotic vs Eukaryotic C. Wyman et al. /DNA Repair 3 (2004) 827–833

  13. References • Fillipo et al. Mechanism of Eukaryotic Homologous Recombination. 2008. Annual Rev. Biochem. 77:229-57. • Lodish et al. Molecular Cell Biology. 1999. W. H. Freeman. 4th edition. • Oldenburg et al. Recombination-mediated PCR directed plasmid construction in vivo in yeast. 1997. Nucleic Acids Research. Vol. 25, No. 2. • Wyman et al. Homologous recombination-mediated double-strand break repair. (2004) DNA Repair. 3:827–833.

  14. Questions?

More Related