Nucleotides and Nucleic Acids - Lehninger Chapter8. 8.1 Basics 8.2 Structure 8.3 Chemistry 8.4 Nucleotide Function . 8.1 Basics. Building Blocks Canonical and Minor Bases Phosphodiester bonds Naming and Drawing Base Stacking and Pairing. Building Blocks.
Two Strands have complementary sequences
2 logical operations to obtain complementary strand 5' to 3'
1. Reverse: Rewrite the sequence, back to front
2. Complement: Swap A with T, C with G
Multiple Degrees of Rotational Freedom
A form – favored by RNA
B form – Standard DNA double helix under physiological conditions
Z form – laboratory anomaly,
Requires Alt. GC
High Salt/ Charge neutralization
Calculated from helix thermodynamic parameters
Loop entropy considerations
Salt dependence is more dramatic
DNA sequences can spontaneously re-anneal and form helices
Basis for many of molecular biology techniques.
PCR, DNA sequencing
Millions of DNA fragments isolated, amplified by PCR and monitored in parallel
Jay Shendure & Hanlee Ji
Nature Biotechnology 26, 1135 - 1145 (2008)
Published online: 9 October 2008doi:10.1038/nbt1486