Lecture 9 - BIS101-001 2/9/09 Lecture 9: DNA replication...

Info iconThis preview shows pages 1–21. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: BIS101-001 2/9/09 Lecture 9: DNA replication continued Mutations and DNA repair LECTURE 9 Outline: The replication fork Special replication of chromosome ends Mutations Types of mutation Mechanisms of spontaneous mutation Induced mutation DNA repair Repair mechanisms, damage tolerance Double-stranded break repair- homologous recombination- non-homologous end-joining 1) Initiation 2) Unwind strands 3) Polymerize 4) Clean up and connect DNA Replication DNA can only be synthesized in one direction-this creates a problem Ligation of nicks is catalyzed by DNA ligase adenosine triphosphate Topoisomerases (e.g. DNA gyrase) can interconvert DNA topoisomers The Replication Fork Helicase strand separation Primase RNA primer synthesis Single-stranded binding protein ssDNA stabilization DNA polymerase III + clamp DNA synthesis Also: DNA pol I, ligase Replication Initiates at Multiple Origins in Eukaryotes O rigin R ecognition C omplex Helicase = MCM complex Licensing factors = Cdc6 + Cdt1 Licensed origin Initiation of Replication in Eukaryotes: Once and only once per cell cycle (highly regulated) LECTURE 9 Outline: The replication fork Special replication of chromosome ends Mutations Types of mutation Mechanisms of spontaneous mutation Induced mutation DNA repair Repair mechanisms, damage tolerance Double-stranded break repair- homologous recombination- non-homologous end-joining The End Replication Problem A special mechanism is required to replicate telomeres eventually essential sequences will be lost and the cells will die (or the chromosome will lose its end-protective function, see next lecture) Telomerase extends the 3 -strand of the telomere without a complementary DNA template. Telomerase uses its intrinsic RNA molecule as template for the addition of nucleotides to the 3 G-rich strand Which is not a substrate for DNA polymerase III: A. 5_______3 3 5 B. 3____5 5 3 C. 3_____5 5 3 D. 5____________3 3 5 Which of the following is not similar between DNA Polymerase and telomerase? A. Both extend using a 3 end B. Both use dNTPs C. Both require a template D. Both have a RNA component LECTURE 9 Outline: The replication fork Special replication of chromosome ends Mutations Types of mutation Mechanisms of spontaneous mutation Induced mutation DNA repair Repair mechanisms, damage tolerance Double-stranded break repair- homologous recombination- non-homologous end-joining 5 A3...
View Full Document

Page1 / 52

Lecture 9 - BIS101-001 2/9/09 Lecture 9: DNA replication...

This preview shows document pages 1 - 21. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online