6_T&T

Lehninger Principles of Biochemistry

Info iconThis preview shows pages 1–17. Sign up to view the full content.

View Full Document Right Arrow Icon
Lecture 5 Helicase mechanism and assays The Coiling Problem DNA supercoiling Topoisomerase Type I Type II The end problem Telomerase
Background image of page 1

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

View Full DocumentRight Arrow Icon
Reading 24 | pp. 954-961 26 | pp. 1053-1056 © 2009 W. H. Freeman and Company
Background image of page 2
DNA Helicase
Background image of page 3

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

View Full DocumentRight Arrow Icon
DNA binding loops pull ssDNA through the center of a helicase
Background image of page 4
Helicase Assays
Background image of page 5

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

View Full DocumentRight Arrow Icon
Determining helicase directionality
Background image of page 6
DNA Supercoiling
Background image of page 7

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

View Full DocumentRight Arrow Icon
Supercoiling of Plasmid DNA Normal plasmid DNA in bacteria is usually supercoiled
Background image of page 8
Background image of page 9

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

View Full DocumentRight Arrow Icon
DNA Underwinding Promotes Supercoiling or Strand Separation
Background image of page 10
Linking Number Linking number in relaxed DNA: number of base pairs divided by the number of base pairs per helical turn Relaxed circular dsDNA of 2,100 base pairs in the B form (10.5 base pairs per turn) has linking number of 200
Background image of page 11

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

View Full DocumentRight Arrow Icon
Linking Number = 25 263 bp of DNA
Background image of page 12
Linking Number = Twist + Writhe
Background image of page 13

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

View Full DocumentRight Arrow Icon
Background image of page 14
Changing Linking Number introduces strain
Background image of page 15

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

View Full DocumentRight Arrow Icon
Topoisomers Differ by Linking Number Compact negatively supercoiled DNA travels fastest in the agarose gel electrophoresis experiment
Background image of page 16
Image of page 17
This is the end of the preview. Sign up to access the rest of the document.

This document was uploaded on 06/14/2011.

Page1 / 38

6_T&T - Lecture 5 Topology & Telomeres Helicase...

This preview shows document pages 1 - 17. Sign up to view the full document.

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