Spring 09 lecture 04

Spring 09 lecture 04 - Nucleic Acid Structure and...

Info iconThis preview shows pages 1–6. Sign up to view the full content.

View Full Document Right Arrow Icon
Nucleic Acid Structure and Hybridization DNA and RNA structure Learning Objectives: Explain the chemical forces determining DNA structure. Describe the conformational features of A, B, and Z DNA structures and when each structure occurs in vivo. Describe how base pairs can be identified in the major groove based on H-bond donors and acceptors.
Background image of page 1

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

View Full DocumentRight Arrow Icon
Different forms of DNA B-DNA Approximately 10 base pairs per turn Turn is every 3.4 nm Bases are perpendicular to the helix axes Right handed Represents most of the in vivo DNA
Background image of page 2
- 11 pairs/turn, turn every 2.8 nm, right handed - bases exhibit a tilt with respect to the helix axis (20 degrees) - found in low water content (lower then normally found in the cell) - DNA-RNA and RNA-RNA helices in a test tube (but it might exist in vivo as well - locally and temporarily) - A-like DNA found in dormant spores of Bacillus A-DNA
Background image of page 3

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

View Full DocumentRight Arrow Icon
12 base pairs/turn, turn every 4.5 nm, tilt 7 degrees, left handed found in test tubes when very high salt conc. first found in d(CG) polymers role in regulation of gene expression: discovery of proteins with Z-DNA binding domains; new discovery: Z-DNA in promoter regions of some genes (including housekeeping) - regulation Implicated in chromosomal breakages and large- scale deletions/rearrangements (in mammals) 2008: implication in Alzheimer’s disease Z-DNA
Background image of page 4
Formed when purines make one strand and pyrimidines the other – then the third strand could be accommodated In test tube, but also likely in vivo during DNA recombination or repair gene therapy possibilities Triple-helical DNA Quarterly Reviews of Biophysics 35 , 1 (2002), pp. 89–107. " 2002 Cambridge University Press Triplex-forming oligonucleotides : principles and applications Karen M. Vasquez1 and Peter M. Glazer2,*
Background image of page 5

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

View Full DocumentRight Arrow Icon
Image of page 6
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 22

Spring 09 lecture 04 - Nucleic Acid Structure and...

This preview shows document pages 1 - 6. Sign up to view the full document.

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