武汉大学 分子生物学全部课程 3
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consequence of the way that adenine and thymine,and guanine and cytosine, pair with
each other. (Related to replication and transcription)
3
DNA STRUCTURE ( )
N1
DNA STRUCTURE ( )
Each bases has its preferred tautomeric form (Related to Ch 9)
2
DNA STRUCTURE ( )
The two strands of the double helix are held together by base pairing in an antiparallel orientation, Which is a stereochemical
Space-filling model
Nucleoside & Nucleotide, the fundamental building block of DNA
phosphoester bond
glycosidic bond
Phosphodiester linkages: repeating, sugar-phosphate backbone of the polynucleotide chain
Welcome Each of You to My Molecular
Biology Class
Molecular Biology of the Gene, 5/E --- Watson et al. (2004)
Part I: Chemistry and Genetics Part II: Maintenance of the Genome Part III: Expression of the Genome Part IV: Regulation Part V: Methods
have the complementary sequence 3’-
4
TACAG-5’
(Related to replication and transcription)
The strictness of the rules for “Waston-Crick” pairing
derives from the complementarity both of shape and of hydrogen bonding properties between adenine and thymine and between guanine and cytosine.
3/08/05
CHAPTER 6
The Structures of DNA and RNA
How do the structures of DNA and RNA account for their functБайду номын сангаасons?
OUTLINE
1.DNA Structure 2.DNA Topology 3.RNA Structure
A:C incompatibility
DNA STRUCTURE ( )
Hydrogen Bonding Is Important for the Specificity of Base Pairing
➢ The hydrogen bonds between complementary bases contribute to the thermodynamic stability of the helix (why?) and the specificity of base pairing
DNA polarity: is defined by the asymmetry of the nucleotides and the way they are joined.
Bases in DNA
adenine
purines
N9
guanine
cytosine
pyrimidines
thymine
3/08/05
Part II: Maintenance of the Genome
Dedicated to the structure of DNA and the processes that propagate, maintain and alter it from one cell generation to the next
Maintenance of the Genome
Ch 6: The structures of DNA and RNA Ch 7: Chromosomes, chromatins and the nucleosome Ch 8: The replication of DNA Ch 9: The mutability and repair of DNA Ch 10: Homologous recombination at the molecular level Ch 11: Site-specific recombination and transposition of DNA
DNA STRUCTURE
DNA STRUCTURE ( )
DNA is composed of polynucleotide chains
Structure: twisting around each other in the form of a double helix.
1
Schematic model
The Two Chains of the Double Helix Have Complementary Sequences
Watson-Crick Base Pairing
Example: If sequence 5’-ATGTC-3’ on
one chain, the opposite chain must
5 ➢ Stacking interactions between bases
significantly contribute to the stability of DNA double helix
each other. (Related to replication and transcription)
3
DNA STRUCTURE ( )
N1
DNA STRUCTURE ( )
Each bases has its preferred tautomeric form (Related to Ch 9)
2
DNA STRUCTURE ( )
The two strands of the double helix are held together by base pairing in an antiparallel orientation, Which is a stereochemical
Space-filling model
Nucleoside & Nucleotide, the fundamental building block of DNA
phosphoester bond
glycosidic bond
Phosphodiester linkages: repeating, sugar-phosphate backbone of the polynucleotide chain
Welcome Each of You to My Molecular
Biology Class
Molecular Biology of the Gene, 5/E --- Watson et al. (2004)
Part I: Chemistry and Genetics Part II: Maintenance of the Genome Part III: Expression of the Genome Part IV: Regulation Part V: Methods
have the complementary sequence 3’-
4
TACAG-5’
(Related to replication and transcription)
The strictness of the rules for “Waston-Crick” pairing
derives from the complementarity both of shape and of hydrogen bonding properties between adenine and thymine and between guanine and cytosine.
3/08/05
CHAPTER 6
The Structures of DNA and RNA
How do the structures of DNA and RNA account for their functБайду номын сангаасons?
OUTLINE
1.DNA Structure 2.DNA Topology 3.RNA Structure
A:C incompatibility
DNA STRUCTURE ( )
Hydrogen Bonding Is Important for the Specificity of Base Pairing
➢ The hydrogen bonds between complementary bases contribute to the thermodynamic stability of the helix (why?) and the specificity of base pairing
DNA polarity: is defined by the asymmetry of the nucleotides and the way they are joined.
Bases in DNA
adenine
purines
N9
guanine
cytosine
pyrimidines
thymine
3/08/05
Part II: Maintenance of the Genome
Dedicated to the structure of DNA and the processes that propagate, maintain and alter it from one cell generation to the next
Maintenance of the Genome
Ch 6: The structures of DNA and RNA Ch 7: Chromosomes, chromatins and the nucleosome Ch 8: The replication of DNA Ch 9: The mutability and repair of DNA Ch 10: Homologous recombination at the molecular level Ch 11: Site-specific recombination and transposition of DNA
DNA STRUCTURE
DNA STRUCTURE ( )
DNA is composed of polynucleotide chains
Structure: twisting around each other in the form of a double helix.
1
Schematic model
The Two Chains of the Double Helix Have Complementary Sequences
Watson-Crick Base Pairing
Example: If sequence 5’-ATGTC-3’ on
one chain, the opposite chain must
5 ➢ Stacking interactions between bases
significantly contribute to the stability of DNA double helix