title: Base pairing structure in the poly d(G-T) double helix: wobble base pairs.
abstract: High resolution nuclear magnetic resonance (NMR) and ethidium bromide binding studies are used to demonstrate that poly d(G-T) forms an ordered double helical structure at low temperatures (below 24 degrees C in 0.3 M NaCl) in which G and T are hydrogen bonded together in a wobble base pair hydrogen bonding scheme as proposed earlier by Lezius and Domin. Alternative hydrogen bonding schemes involving the tautomeric form of either T or G, such as have been proposed to account for mutation rates in DNA synthesis, are eliminated.
mesh_terms: D055598:Chemical Phenomena; D002621:Chemistry; D003848:Deoxyguanine Nucleotides; D004996:Ethidium; D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy; D009690:Nucleic Acid Conformation; D011089:Polydeoxyribonucleotides; D013942:Thymine Nucleotides
chemical_list: D003848:Deoxyguanine Nucleotides; D011089:Polydeoxyribonucleotides; D013942:Thymine Nucleotides; C017650:polydeoxy(guanine-thymine) nucleotide; D004996:Ethidium