An NMR study of the conformation and thermodynamics of the circular dumbbell d [formula: see text] Slow exchange between two- and four-membered hairpin loops.
The circular DNA decamer 5'-d [formula: see text] 3' is studied in solution by means of NMR spectroscopy. At low temperature the molecule adopts a dumbbell structure with three Watson-Crick C-G base pairs and two two-residue loops in opposite parts of the molecule. On raising the temperature another conformer appears, in which the closing C-G base pair in the 5'-GTTC-3' loop is disrupted, whereas the opposite 5'-CTTG-3' loop remains stable. The two conformers are in slow equilibrium over a limited temperature range.
Ippel
J H
JH
Department of Organic Chemistry, Leiden University, The Netherlands.
Lanzotti
V
V
Galeone
A
A
Mayol
L
L
van den Boogaart
J E
JE
Pikkemaat
J A
JA
Altona
C
C
D001482:Base Composition; D001483:Base Sequence; D004270:DNA, Circular / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009838:Oligodeoxyribonucleotides / Q000737:chemistry*; D011522:Protons; D013816:Thermodynamics
D004270:DNA, Circular; D009838:Oligodeoxyribonucleotides; D011522:Protons