dna structures dr. helen berman september 18, 2002
TRANSCRIPT
DNA Structures
Dr. Helen Berman
September 18, 2002
Canonical DNA
Helical parameters
Conformation angles
Groove dimensions
Neidle, Stephen. Nucleic Acid Structure and Recognition.Oxford University Press, 2002, pp. 33, 35.
B DNA
Neidle, Stephen. Nucleic Acid Structure and Recognition.Oxford University Press, 2002, p. 34.
B DNA View down helix axis
Voet, Donald and Judith G. Biochemistry.John Wiley & Sons, 1990, p. 799.
Space filling B DNA
Voet, Donald and Judith G. Biochemistry.John Wiley & Sons, 1990, p. 796.
Defined sequence DNACGCGAATTCGCG
High propeller in center
Narrow minor groove
Spine of hydration
Voet, Donald and Judith G. Biochemistry.John Wiley & Sons, 1990, p. ###
Voet, Donald and Judith G. Biochemistry.John Wiley & Sons, 1990, p. ###
Neidle, Stephen. Nucleic Acid Structure and Recognition.Oxford University Press, 2002, p. 97.
A DNA•Right handed•Bases tilted•Deep major groove
Neidle, Stephen. Nucleic Acid Structure and Recognition.Oxford University Press, 2002, p. 36.
A DNA
Voet, Donald and Judith G. Biochemistry.John Wiley & Sons, 1990, p. 800.
Defined sequence
CG rich
Conformation of Z DNA
2 nucleotide repeat
Neidle, Stephen. Nucleic Acid Structure and Recognition.Oxford University Press, 2002, p. 33.
Z DNA
•Left handed•Very deep minor groove•Major groove on outside
Voet, Donald and Judith G. Biochemistry.John Wiley & Sons, 1990, p. 802.
Defined sequenceCGCGCG
Mismatches
GT
•Local changes•Global structure same as parent
PNATriple strand
DNA strand+
Peptide nucleic acid sequence
Quadruplex DNA
G pairing in quadruplex
Neidle, Stephen. Nucleic Acid Structure and Recognition.Oxford University Press, 2002, p. 76.
Diversity of folds
Two different dimer folds
Also possible•single strand•four strands
Neidle, Stephen. Nucleic Acid Structure and Recognition.Oxford University Press, 2002, p. 77.
Holliday junction
formed by 4 decamer strands
Voet, Donald and Judith G. Biochemistry.John Wiley & Sons, 1990, p. ###
Voet, Donald and Judith G. Biochemistry.John Wiley & Sons, 1990, p. ###
Neidle, Stephen. Nucleic Acid Structure and Recognition.Oxford University Press, 2002, p. 83.
4 way junction
RNA-DNA complex with
a junction structure